Ever stumble on a good deal for a used part

Best deal I turned over. Knew a guy from my town, said he had a shifter for
a mopar. He didn't know what for. I go and look at it. Complete 4 speed
shifter for a 69-69 B body with a console. I asked him what he wanted for it?
He said; how about $20.00. I said sure! I didn't give him any clue on what
it was really worth.
Kept it for about a month and resold it at a show in the sothern part of the
state. Before i could get it out of the box, I had two guys interested.
Sold it for $450.00. I think that was a good profit. I did not rake anyone
over the coals, they were biding against each other. I wasn't going to say
anything.