STI does not have a long life, but maybe an ultrasonic cleaning might help...? See the ultrasonic thread.
Anyway, values right now are in the dumps, vacation, economy, take your pick.
I saw a 55 cm Grandis on ebay, $350 buy it now or best offer, sold for $275. !!? It was drivable from me, and he would do local pick up... I don't have the cash, but if I had been hard hearted enough to offer $280. maybe it could have been mine, a tremendous value even though I suspect it was repainted. It is bleak out there.