Seems like a nice hack, assuming nobody made an argument that it constituted "public performance" or something similarly crazy.
Plus, you get automatic coverage of damaged disks: the company will buy back undamaged disks for what you paid minus the rental fee, or for full price in the case of an all-you-can-watch service.
Except anything with a low/bid ask spread becomes money and that comes with its own set of problems. What would happen if the DVD was sold back for more than it was bought for? It's the intersection of Banking + Copyright + Tax Law. The trifecta of screwball legal areas.
Plus, you get automatic coverage of damaged disks: the company will buy back undamaged disks for what you paid minus the rental fee, or for full price in the case of an all-you-can-watch service.