I had a friend from high school that got all twisted out of shape over what he thought was a scam for the same amount of money. He wanted a muscle car; I found him a '70 GTO with a very good body that needed mechanical work and paint but was all there. In the deal I convinced the guy to throw in a fender and door for my Firebird, grand total for the GTO and the other parts was $175, up from the asking price of $150 for just the car (ah, the good old days). I put in $75 for my stuff, leaving $100 for the GTO, which my friend paid gladly.
That was fine for about a week, but then he started wondering if I somehow got my parts cheaper than I otherwise would have by making that part of the deal. Then he got the idea that I had tricked him into wanting a muscle car so I could buy the fender and door and insisted that I buy back the GTO, which I did on the spot. Then THAT made him think that I now had maneuvered him into selling me the GTO and that he was getting shafted again! I told him to make up his mind and tell me what he wanted to do. He bailed, I kept the GTO for a while then took off the disc brakes, kept the #16 heads that were in the back seat along with the dual-point Mallory distributor and a few other pieces and sold the rest to clean up the yard.