Ask HN: Data Source for Book Metadata

I'm looking for up-to-date book metadata (for a side project) but have been having a hard time finding anything remotely suitable.

There are some interesting free data sources, like isbndb, but they, specifically, don't seem to aggregate varying editions under a single title.

I'm happy to pay. Ingram content provides potentially suitable web service for consumption, but if you're not a library or physical book retailer access to their metadata costs at minimum $500/month with very strict usage terms.

I've checked out various others, including librarything, goodreads api, and so on but none seem compatible with usage that could be aspirationally commercial.

And ideally I'd prefer to avoid Google or Amazon's Product APIs.

There have been peripherally related discussions in HN comments before for threads such as:

"I Want to Fix GoodReads" https://news.ycombinator.com/item?id=24454221

"Goodreads’ reign over the world of book talk might be coming to an end" https://news.ycombinator.com/item?id=24451428

Themoviedb, rawg, and similar exist for other mediums, why does print seem to be so much less developer-friendly? Hopefully I'm just wrong and folks can provide alternatives, but hoping to open this question up to a wider audience.

Thanks!