its been proposed many a time, the problem being that everyone wants it to be their payment scheme and every site wants more than users are willing to pay.
It's exactly like cable, and I think it would suck for the same reason I think cable sucks. Packaged deals like that are only convenient to the customer because payments are brill inconvenient. So you get stuck paying for a bunch of shows and programs you don't want, and thus funnel money away from content creators you enjoy and toward content creators that are good at making deals with the cable company.