Edition-change index card
Paste what actually changed between editions and what each one costs, and get cost per changed chapter instead of a guess.
1 · List the editions and what changed
FIRST-LOAD
Data note: Your edition notes stay in the browser tab; nothing is sent to a bookstore or a publisher and no account is created.
Perspective: Before: the reader assumed a new edition meant new material. After: they can see the new edition rewrote three of fourteen chapters and costs $32 per changed chapter.
2 · Read the per-chapter figure
Paid layer: the edition file
one-time step · the free reading above stays complete
Free tier
- one complete card
- cost per changed chapter
- state link that reopens the same edition notes
What $5 one-time adds
- four editions held on this device
- printable comparison card
- CSV of every edition and change count
One avoided hardback at $96 is 19× the price; the comparable it undercuts is the campus bookstore's shrink-wrapped bundle, which costs more than this card.
Local history (this device)
- No saved runs yet — your first run files here.
Your purchase is handled through secure checkout. When you return, your extras are ready on this device — no account, no fuss, and your work stays private in this browser.
Boundary and sources
This card prices changes you describe; it cannot know what your course requires. Reading lists, assessment text and lecturer instructions override any number here, and a cheaper edition is not always acceptable for an exam. Confirm with your department before buying, and treat second-hand sellers' descriptions as claims to check.
- Change counts and prices are the reader's own notes; no publisher claim is repeated as fact.
- Where a change list is unavailable, the card says so rather than assuming every page changed.
- Errata sheets and preprint corrections are treated as user-supplied evidence, not verified data.
Mechanism: prediction-error-curiosity