Pawn Star Question:

Watching old Pawn Star shows and it made me to wonder: Clearly, they don't sell everything they bring in on the show: Griswold's jacket, the barber show, Coke machine are still in the shop and who knows what else they have in the back or outside the store. My question, are they actually making money from the the items they bought on the show? Does the show reimburse them if they don't make a profit?
We already know that the History Channel or a producer pay them for the shows, so does the History Channel or a producer subsidize their purchases?