Ikea shelving

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Ikea Shelving
When word spread in February 2014 that IKEA would be discontinuing its popular Expedit shelves, its average selling price on eBay shot up 23 percent—from about $94 to $116—according to the auction website's sales data. The shelves' simple, goes-with-anything design makes them a staple in $12-million homes and studios alike, says Jeremiah Brent, interior designer and curator for eBay, especially since they can be used individually or stacked to mimic floor-to-ceiling bookshelves. (And, as Lifehacker's tutorials prove, can be used to make bed platforms, benches, storage tables and TV stands. If you're over the look, reselling yours could fund your next living room mini-makeover.
Tablet

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Tablets and Smartphones
Many major retailers are making it easy for you to resell your old tablets, cell phones and other electronics. Best Buy, Walmart, Amazon, GameStop and Target all have programs that allow you to instantly get a price quote for your old gadget and sell it to them in exchange for a gift card or credit toward an electronics purchase. Amazon and Walmart offer the most—up to $300 for an old tablet—and most companies will base the resell value on a few key questions: Is the screen cracked? Does it turn on? Is it fully functional? Are there any dead spots in the LCD display? Your tech toy doesn't have to be in mint condition to be resold, and most companies will give you a price quote online immediately—no haggling or hustling necessary.
Coffee table books

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Coffee Table Books
If that gorgeously photographed hardcover is doing little more than keeping your bud vase and votives company, you may want to Google it to see how much a used copy is selling for. Many home design, fashion and jewelry books really hold their value—and in some cases, can be worth more than you originally paid for them. Three highly sought-after titles are Christie's Auction Collection Yves Saint Laurent et Pierre Bergé, which sells for about $399; Emilio Pucci by Vanessa Friedman and Alessandra Arezzi Boza, for about $45; and Vogue Living: Houses, Gardens, People by Hamish Bowles and Calvin Klein, which brings in about $34, says Brent.
Designer collaborations

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Discount Designer Collaborations
Sitting by your computer at midnight to get the first pick of Target's latest designer collaborations could come with a major payoff, particularly if you own anything from its partnerships with Missoni, Jason Wu or Phillip Lim. A Missoni-designed bicycle, for example, originally sold at Target for $399 when the line launched in 2011, but on eBay, it's selling for up to $1,280, eBay reports. Similarly, the Jason Wu for Target blue satchel bag you originally bought for $40 could bring in as much as $230.
Classic exercise video

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Classic Exercise Videos
The more out-of-date you think a workout video is, the more reason you have to spare it from the trash can. Classic titles, like Jane Fonda's Complete Workout, are worth about three times as much as current favorites, says Brett Lauter, U.S. president of Decluttr.com, a site that buys used CDs, DVDs and games. It's a textbook case of scarcity: The older videos aren't as widely available anymore, so people are on the hunt for them (and it doesn't hurt that Jane Fonda looks as incredible today as she did in 1989, when Complete Workout was released).

If you don't want to deal with the hassle of selling everything yourself, Decluttr will buy the DVDs from you—even if it's a title they can't sell, they promise to pay you at least 50 cents for it—and will cover all shipping costs. The company offers $1-$2 for many exercise videos, though Fonda's is worth close to $5 and Richard Simmons's Sweatin' to the Oldies comes in at $2.63.
Bicycle

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Bicycles
If you've got a slightly rusty but perfectly functional bike hanging out in your shed, good news: There's someone out there who wants to display it in his loft. Favored types include early BMX models (manufactured between 1965 and 1980), Raleigh and penny-farthings. If the bike is in good condition and appeals to a collector, it can be worth between $200 and $500. A surprising warning: "Please don't restore the bike before you sell it," says Patrick van der Vorst, founder of ValueMyStuff.com. "Collectors of bicycles want to restore them themselves; hence, any restoration you would do might actually take away from the value of the piece."
Mickey Mouse

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Disney Memorabilia
"I sold a Disneyland T-shirt that I got at a thrift store for 50 cents for $12," says Jim Griffith, eBay's dean of education and author of The Official eBay Bible. "It was rare because it was Halloween-themed." But even more-recent, less-unusual items—a pair of Princess Jasmine sheets that haven't left the linen closet in 10 years, for example—are snapped up by fans. And, if you're still hanging on to a bunch of old VHS tapes, or if you've abandoned DVDs in favor of Netflix, now is the time to sell. Disney released a series of its movies in four special editions between 1984 and 2009: Walt Disney Classics (1984 to 1994), Walt Disney Masterpiece Collection (1994 to 1999), Walt Disney Gold Classic Collection (2000 to 2001) and Walt Disney Platinum Editions (2001 to 2009). Check to see if your case is labeled as one of those four editions. If it is, each tape or DVD is worth between $5 and $50.
Midcentury modern chair

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Midcentury Modern Furniture
You know that chair? The one that your downsizing relative foisted on you that you absolutely hate and swore you would never use? If it was purchased between 1930 and 1965, finding a buyer for it won't be hard. Eames items are particularly coveted, as are those by Arne Jacobsen, Harry Bertoia, Eileen Gray, Borge Mogensen, Isamu Noguchi and Herman Miller. If you're looking to get the highest possible price, check for any designer names on the piece and then research the names to see if you've got a rare find on your hands. And if the manufacturer doesn't seem particularly remarkable, don't despair. Griffith says even a generic end table from that period can be worth $50 to $100.
Vintage suitcases

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Old Suitcases
"There's a growing trend for vintage suitcases, especially the leather ones or the very early plastic models," says van der Vorst. This particular market is very focused on brands; buyers look for early pieces from Louis Vuitton, Mulberry and Burberry. But if the gorgeous cognac brown leather case your grandparents used to take on vacation is not covered in LVs, you can still get a good price for it as long as it's in good shape on the outside. The lining doesn't even have to be in perfect condition, nor do the locks, although the fewer the flaws the better. As for plastic, aspiring Betty Drapers and Pan Am enthusiasts alike will flock to a retro hard-shell piece that you've always found too clumsy to take to the airport. Here brand names are less important; it's the modern look that collectors covet. A designer leather piece without exterior damage can go for as much as $30,000, while less-known brands sell for $200 to $400. Plastic suitcases in good condition fetch up to $2,000.
Mixer

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Kitchenware
The old-school Mixmaster is making a comeback. "Most people steer clear of buying older electric goods because of issues of fire and safety, but a lot of those items have become quite iconic in their design and their style," says van der Vorst. Mixers, coffee makers and even Bakelite toasters regularly go for several hundred dollars at auction. Collectors are particularly interested in early Cuisinart appliances, perhaps taking a cue from Steve Jobs, who was a fan of the brand's contemporary designs.
Old-fashioned metal lunch box and thermos

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Lunch Boxes
Once upon a time, you treasured your Jetsons lunch box. Now it sits on a shelf in your mother's basement. Someone out there would like to make it feel loved once again—and possibly pay you thousands for the privilege. In general, you know you've got a valuable piece if it features a cult TV show (Star Trek is hugely popular) or a comic book hero like Superman. The 18th edition of Toys & Prices, a guide which lists values for collectibles, says plastic lunch boxes currently sell for between $30 for common models and $150 for harder-to-find items like a 1964 Popeye, Truant Officer lunch box by King Seeley. Steel lunch boxes are more prized than plastic and go for between $65 for everyday models and $5,500 for a rare 1978 240 Robert by Aladdin. As for that box in which little you carted PB&Js and carrot sticks, the 1963 Jetsons Dome by Aladdin is currently valued at $2,650 (plus $375 for the thermos bottle if you've still got it).

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Polaroid Cameras
Most of us carry a camera every day in the form of our cell phones and keep a digital point-and-shoot around for special occasions. But the charm of film endures—in particular, people are willing to pay for Polaroid cameras. The most sought after types are the Model 100 from the early '60s, the SX-70 and the Spectra series. An SX-70 in decent condition sells for around $100, but a carefully preserved one can be worth up to $500. You can sell less-popular versions in good condition for $20 to $50. If you've long since given away your camera, but you find a few packs of instant film stashed in a drawer, don't toss them. They go for around $10 each.
Jewelry

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Costume Jewelry
Unique jewelry pieces can be sold with a heavy price tag, especially if they have their original stamp or maker's mark. At JewelryWonder.com, you can set up an online store by uploading photos of pieces you own. If the jewelry was passed down by a relative or looks as if it's a few decades old, it might be just the thing costume jewelry enthusiasts are eager to get their hands on. Pieces by Trifari, a jewelry company popular in the '30s, can be distinguished by its trademark "T" stamp with a crown above it. Other sought-after pieces are Eisenberg Ice, especially pins made of Swavorski crystal (marked with "Eisenberg Originals") from the '30s.
Pottery

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Pottery
"We once had a client who had a pottery vase they were using as a toilet brush holder," says Stuart Whitehurst, vice president of Skinner, Inc. auctioneers in Boston. "They had no idea it was made in the late 1800s by Boston pottery maker William Grueby and that its yellow glaze was extremely rare. That toilet brush holder ended up being worth $18,000." So how do you know if Grandma's umbrella stand is actually precious pottery? JustArtPottery.com has a large gallery of patterns and frequently publishes articles on how to tell what kind of pottery you own. And one of the hottest items on the market right now, Whitehurst says, is Chinese porcelain. Commonly found in a traditional blue and white motif, it's now exceptionally popular because Chinese collectors are trying to reclaim pieces that were brought to the States by American missionaries in the 20th century.
Toys

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Vintage Toys
Pez, Barbies, figurines from popular cartoons like the Smurfs or Snoopy—any toy that brings back a little nostalgia could be something a collector will pay big money for. There are certain rarities to look out for, says Whitehurst, like Barbies with a side part and bubble haircut (which were mostly sold in Europe in the '60s and are now highly sought after by American collectors) or a Pez dispenser with a patent number (found toward the bottom of its stem) of 3.9 or lower, which means it was manufactured before 1976.

ToyCollectorNetwork.com allows you to sell, learn more about and keep track of your classic toys online.