A solution is surely simple?
Digital data is simply ones and zeroes. Charging differently for those ones and zeroes depending on what they build is daft as each one takes the same amount of resources to pass along.
So improve something else, such as
* Improved latency
* Decreased contention
* Dual redundancy (e.g. with some routers you can have both an ADSL and 3G modem providing WAN simultaneously so you, theoretically, have no downtime- pretty useful in the sticks or if there's a problem at the exchange)
* ISP-level filtering for parents, with a password that allows the parents unfettered access. You know, rather than getting anyone who wants anything interesting to sign up saying 'yes, I'm a pervert, monitor me!'.
Or with a bit more work:
* Host the popular videos from Netflix and the like on their local network, redirecting requests for the Netflix server to their own. This way they pay less for external bandwidth and the user gets faster streaming while ALSO getting rid of some of the slowdown you get when it's a highly-watched video (say, Brian Griffin's last scene or Game of Thrones S4 when it comes out). Similarly, Steam content could be held on these servers too.
I think they already do buffering like this, but more deliberate and charged for.
* Host high-speed, ISP-network dedicated servers for popular online games- so players on that ISP would naturally have some advantage. Have some sort of competition, maybe a prize or two. This could not only be a good 'premium' service but also persuade gamers to swap ISP if it was a generally good ISP too.