Free tool
Shopify Store Price Audit
Type a store domain. This reads the same public product feed a shopper's browser can read, and tells you what its prices look like right now.
What you get
How many variants are showing a crossed out price at this moment, which compare at values are sitting there doing nothing, which prices ended up with the leftover cents a percentage discount produces, and how many price writes a full catalogue sale would take.
Everything here comes from the product feed Shopify publishes for every store, the same URL a browser can open. It is a read, not a scan, and nothing about the store is saved.