This 2000 Ford Ranger XLT was my annual, "Oops!". I got it for only $1300 with 135k miles on it. But I thought I could just replace the head gasket and everything would be fine with the engine going forward.
It wasn't. So I decided to find the lowest mileage engine in Georgia and used that as the foundation for getting a premium price for it. The Ranger got that engine for about twice the price of a high mileage one. A new clutch, belt, plugs, wires, water pump, and I even found brand new seats that were stored in an attic for 12 years.
I put it online for $3900 and sold it for $3700. About a $700 profit. The last words from the buyer before he drove off were, "I sure love how you do your business!"