It looks like this API is only returning pricing data if the Amazon product detail page (PDP) matches a specific format or layout. As Amazon uses multivariate testing on its PDPs to optimize to conversion rate, that means many product detail pages will vary their layout.

Here’s what I found.

The following examples use Amazon’s traditional PDP:
https://www.amazon.com/dp/B09G91LXFP
https://www.amazon.com/dp/B08PZD76NP
https://www.amazon.com/dp/B09HF1DC1J
https://www.amazon.com/dp/B09BRG3MZ2
https://www.amazon.com/dp/B09327XWMP

For the examples above, this API accurately captures price data as current_price.

However, Amazon more often than not varies the PDPs, as shown in these examples:
https://www.amazon.com/dp/B09JQL8KP9
https://www.amazon.com/dp/B0932HVSYM
https://www.amazon.com/dp/B0932FC8XR
https://www.amazon.com/dp/B08N5PHB83
https://www.amazon.com/dp/B09BRD98T4
https://www.amazon.com/dp/B0933BVK6T
https://www.amazon.com/dp/B0931Y6CPF
https://www.amazon.com/dp/B0863BQJMS

With examples like these, this API wasn’t able to capture pricing data for any of the products. The API is returning current_price of 0.

Can this API be updated to capture pricing data across all PDPs?