Startup cost: $50, plus ingredients
How often you need to use it to make it worthwhile: Daily for a summer. While the main reason to invest in a Zoku Quick Pop Maker is the near-instant gratification (it freezes pops in seven minutes), if you live in a place where it makes sense to slurp a frozen treat every night, you could make a wallet-friendly argument, too. A family of three eating one popsicle a day each would go through about 270 popsicles from the beginning of June through the end of August. Store-bought fruit juice-based pops vary in price, but if you're buying pops that cost $1 each, you'll spend $270 in 90 days. Meanwhile, if that family were making their own, they'd spend about 15 cents on juice per pop. Multiply that times 270 pops and you get $40.50. Once you add the cost of the machine ($50), you're at $90.50. Compare that to the $270 cost of buying them from the supermarket, and there's almost $180 left over at the end of the summer to spend on back-to-school supplies.