You have a point on the rich can pay, but I don't see the practicality of it... the rich will always pay no matter what policy you have because well... they're rich. It isn't going to be life limiting and it isn't an awful system of payback. For example, if you are on the higher than average wage of say 30k a year, you pay back £67.50 a month which isn't a whole lot of contribution considering what university gave you. The bad part of this policy is the marketisation of the university system.
The real problem of higher education funding is the maintenance loan as I said in my last post.