It seemed to fail my first test.

I used pagesonpages.com search for "rust", clicked on a search hit (Blandy, et al., Programming Rust, 2e) showing price of $50.84, which loaded the product page on bookdepository.com, showing paperback for $50.84.

Then I separately searched on the Amazon site, and they showed paperback for $32.49 (shipped&sold by Amazon).