I discovered why the “buy the whole book” rate was as low as it was. It wasn’t.

It’s literally just a way to pay 10 points per (remaining) chapter in one go, and I’d missed that the 100 chapters were split into three “books” of 30-ish chapters each.
So the full story would be upwards of $50. I wouldn’t pay that for a hardback!
All the best to the writers who actually do well on the platform, but no love on the publisher’s business model. If you pay for individual chapters you’re paying way over market price for comparable products. If you pay for their subscription you probably won’t get permanent access to the books you read.
I’m like… I shouldn’t get this annoyed by this. But it’s irritating that this company has somehow managed to make bank off of this, both because it’s screwing readers with its pricing model and because it’s probably not giving its authors a much better deal.