I had a discussion with Jim Gandy a few weeks ago (we hang out a lot since we're such good chums after I accidentally won last year) ... he was thinking of proposing this change to the street tyre rules: if you have a treadwear of 140 - 200 or so, you get one handicap, and if it is over 200 (or whatever the higher number ends up being) then you get an even better handicap.
I think this is a good idea, then we can run $80 rubber and still be competitive