Ah gotcha. I have a dream of one day combining the data I am putting together with Storygraph or others and trying to do an at-cost API for book data to encourage more reading/book apps. There is so much free time being put into Goodreads that doesn't seem to do anyone any good.
I did some data management a while back for higher education institutions from Brazil and took that opportunity to contribute to WikiData.
Not a recommendation, just a shoutout to them. Also, OpenRefine helped so much, kudos to all involved.
It's the same thing, but I get what you mean. By expensive, I mean too expensive to get to invest in building it, not as in expensive to buy off-the-shelf.