I"m pretty sure dudes like that are the reason that prices for old beat up jdm **** are so ridiculous.
When people who have no idea of something's true value just start making crap up, it throws the whole thing off.
You paid him, the thing was on your car. He needed to get his ass over there if he needed it. If he could have sold it for all that money, it would have never been on your car in the first place.