My first year in college when I was living in the dorms on campus some dude with a blank white van was trying to sell me some home theater system out of the back of his van. The price was too good to be true, so I passed thinking it was some scam. The next day, two people in the dorms had bought the system and it wasn't working. They got burnt. This prompted the administration to post fliers about people selling faulty equipment with the statement on the bottom saying "If it's too good to be true, it probably is". Those are good words to live by.