I picked up a barn fresh Miyata 912 today. The only real issue is this dent in the chain stay:
It is somewhere between 1/8 and 3/16 of an inch deep. Is this a serious concern? I'm sure breaking a chain stay at 30 mph would be unpleasant. Is this something a frame builder could fix? The bike was cheap enough that I wouldn't mind spending some money for peace of mind.