R33 is a superior car, and the extra wieght is only from good things (more rigid chassis, and gearbox). Even if they are cheaper to buy, i think the running costs will be higher, engine is more, gearbox is more, and less R33 wrecks about to rape and pillege...and even less R33 GT-R's to strip for lightweight parts.
The tourqe would be nice, but there are cheap and legal ways to get tourqe out of a 20