What is even worse than the diamond in the rough deal is the vehicle that wasn't a great deal but where the customer paid more than market price and it is still a piece of junk. I had a 16 year old girl stop at my shop with her mother at closing time recently with an overheating car an older Dodge Neon with 150,000 miles plus. She had bought it from a dealer the day before for $2,500. I raised the hood and took one look at it and found the radiator was full of rusty muddy water with no flow. At a minimum it would need a timing belt, water pump, probably a timing belt kit, a serious flushing, and probably a radiator, at least $700-$1000. I didn't look for any other problems. Her dad had "checked" the car out and bought it because it ran good. Ofcourse he didn't drive it long enough to heat up. Now they are going to have a family friend shade tree mechanic fix it and try to save money. I hate to think about how much money they wind up dropping into this piece of junk after the friend possibly screws it up more.
Those prepurchase inspections can save a lot of grief. We have prevented a lot of people from making horrible purchase decisions. Of course I will never forget the time that we inspected a hunk of junk Hyundai that had been wrecked and improperly repaired. Nothing fit correctly. We showed the customer all of the problems and basically advised against the purchase. They happily paid the inspection fee and then showed up at the shop two days later for us to do some work on this hunk of junk that they had happily purchased. They should have saved their money on the inspection because they didn't listen to a word we said.