The right model, not the cheapest: what a few cents per lesson buys
SuperEscuela started writing lessons with the smallest, cheapest AI model. We measured the quality against what children deserve, and moved to a larger one. Why the saving was never worth it, in numbers.
When SuperEscuela, our non-profit school for Spanish-speaking children, started generating lessons with AI, it began with the obvious choice for a project that is free forever: the smallest, cheapest model available.
Measure the quality, then choose
From January to early April 2026, the content pipeline wrote topics with Claude 3.5 Haiku. Reviewing the output against the bar children deserve (right, clear and pitched at their level, not just fluent), the team moved generation to a larger model, Claude Sonnet 4, on 9 April.
What the larger model costs
This is an estimate, worked out from the volume of content generated and the model’s list price:
Per lesson
2–4¢
Estimated AI cost with the larger model
Whole catalogue
$60–130
To write about 2,800 lessons at that rate
Price ratio
~4×
Larger model’s list price over the smallest’s
Four times the price sounds like a lot until you see the unit: cents per lesson. The difference across an entire school is the cost of a modest dinner.
Where the money really goes
The model bill is the smallest part of AI content. The real investment is the system around it: a strict format every topic must match, written guidance for each age group, alignment with the official curriculum, and people who review the output. Saving cents on the model while spending weeks on that system is the wrong trade.
How to choose
- Start with a sample, not a catalogue.
- Judge quality against your actual readers, not against “sounds fine”.
- Work out the cost per finished unit (a lesson, a page, an answer), not per million tokens.
- Revisit the choice as prices fall: newer models are often both better and cheaper.
The principle
Choose the model by measuring quality. The cheapest model was the first tried and the first replaced.
SuperEscuela is free for every student and teacher, with no ads and no paid plan. Try it, and tell us what you think.
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