"Raced 1000 miles" may be meaningless. The condition of the frame is what is important. I would think having a lot of close up photos of the frame, especially around the drive train...chain slap, etc..., under the bottom bracket shell, etc. would give a better idea of the condition of the frame. Having a bike shop mechanic, etc. look at it is probably "after the purchase". If anything amiss is found where does that leave you and your money? Perhaps having a reputable shop in the sellers area inspect the frame would be a good idea.

A frame may last for a decade as a racer or one trip around the block if it is crashed, etc.