That's what one of my friends did and it worked better. I actually built the website for that campaign. He's a super math geek so he did a bunch of calculations and essentially created a wealth system that had deconstructed a level (saves, bab, feats, skills, CL etc) and created a store on the website where you can purchase those things piece meal. (I think we were using a system called Buy the Numbers). Then the XP system was just wealth in that. It worked out pretty okay until he got a power gamer in who ruined it.