American Pickers

Like I said they have contracts for the stuff they find. On one show they ran into two old gas pumps, the kind that had the gas in a long glass globe on top of the pump so when you pumped your gas you could see that it was clean. They paid the owner a thousand dollars for the pumps (intact but rusty and one globe broken). Before they got them back to the shop their secretary called a black guy who restored old gas station pumps and collected signs and oil cans, etc and they drove over to his shop and sold them to him for $1700. KaChing, + $700. for dragging them out of the weeds.
They do make some bad buys too. They bought an old car for $5K and that was all it was worth. Sometimes you're the windshield and sometimes you're the bug. They the windshield a lot more than not, they know their stuff.