Append a new snapshot each time a real price changes. Google Play Books is always the authoritative current price — this file is a historical reference only, not a live feed.
| Date | Book | Price (USD) |
|---|---|---|
| 2026-07-15 | age-one | $70 |
| 2026-07-15 | age-one-premium | $200 |
| 2026-07-15 | bitcoin-standard | $110 |
| 2026-07-15 | science-feeling-great | $18 |
| 2026-07-15 | art-of-joy | $18 |
| 2026-07-15 | youtube-algorithms | $15 |
| 2026-07-15 | pet-friendly | $7 |
Source: price-history.json, last updated as snapshots are recorded. Currency: USD.