What usually breaks
Price mismatches are rarely one simple bug. They often happen when the storefront price, Product JSON-LD, feed export, sale price window, and currency formatting are controlled by different apps or templates.
Visible priceRead the price a buyer sees above the fold and near the purchase action.
Structured priceInspect Product and Offer JSON-LD for price and priceCurrency.
Feed priceCompare the submitted feed or catalog export against the page.
Sale timingCheck salePrice, salePriceEffectiveDate, timezone, and cache delay.
Variant logicMake sure default variant, selected variant, and canonical URL describe the same offer.
What ProductProof checks first
The free scan compares visible product signals against Product/Offer markup and flags suspicious gaps with evidence. Paid reports add a prioritized fix plan and developer handoff notes.
Best first fix
Use one price source for the storefront, JSON-LD, and feed generation wherever possible. If apps must transform prices, document the order of operations and rescan after cache clears.