In the 1990's, when I was a grad student at
SLAC, research groups usually ordered books (all technical books of some kind) through the SLAC library, because they got a
cheaper library price. The books were stamped and catalogued as library books, but were on essentially permanent loan to the group that had paid for it, though anyone else could find it in the catalog and borrow it from whoever had it.
On another subject, my understanding of US law is that libraries are free to buy books through any retailer and lend them out. What I've read about Redbox's DVD / Blu-
Ray rental kiosks seems to support this. Redbox usually tries to make deals with the movie companies to buy rental editions of discs (usually lacking "extras") at a cheaper price for rental businesses during the rental window, which is earlier than the purchase window, and probably gives a cut of the rental fees back to the movie companies. Disney refused to deal with Redbox for a long time, so Redbox had to buy Disney movies at the same (higher) prices they were sold to consumers buying discs to keep. Disney even sued Redbox when they sold the free digital copy codes that came with the retail discs that Redbox was buying. I think Disney lost. Redbox recently made a deal with Disney so they could have Disney movies on their streaming service, and as a part of that deal, Disney movie discs are no longer eligible for some of the discount codes for Redbox disc rentals.