drove the twin turbo 3 coupe, and the old man is getting one in Jan. Definitely very quick, but ain't GTR territory. 0 - 100 round 5.8 i believe.
In terms of price, i believe the new V8 M3 of 2008 will be very similar price. around the $175k'ish mark. But, the new M3 is going to have to do a lot. But with the 335i coupe already close on the E46 M3, you know BMW will pull out something special for the next M3
on price alone, i think GTR v M3, will be quite similar. I daresay the GTR will demolish the new M3.
on skills alone, the main one is GTR v 997 Turbo. By all accounts, Nissan has got this one pretty much sorted as well