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STEM Subscription Box or One-Off Kit? What Two Weeks of Testing Showed
Cost per hour, return rate and learning depth for KiwiCo and MEL against Snap Circuits, chemistry sets and robots.
August 31, 2026 · 4 min read
Cost per logged hour
- Snap Circuits Jr.: about $4/hour, and it keeps going.
- National Geographic Earth Science: $7.50/hour, single use.
- Thames & Kosmos CHEM C500: $6.70/hour until the reagents run out.
- KiwiCo: about $8/hour per crate.
- MEL Science: about $14/hour, but the most learning per hour.
- Sphero BOLT: $16/hour in two weeks — falling every month it is used.
- LEGO SPIKE Essential: $25/hour in two weeks; a years-long investment.
Return rate
The children came back unprompted most to Sphero, Snap Circuits and the KiwiCo crates. Chemistry sets need an adult, so they happened when an adult was free.
The rule
Buy a one-off kit to find out whether the child likes the subject. Subscribe when they finish it and ask for more.
» See the full rankings: Best Science Kits for Kids, Best STEM Kits Under $50 .