Robert:
Considering the time and effort it takes for you to travel to the various riverboats, pick up the chips and ship, I feel the prices you have listed are FAIR. I am sure that some collectors pick up a few chips and sell for face. I understand the time and effort it tskes to fight the riverboat cages to secure these chips.
Let those that complain dance the dance and see if they still don't understand the cost of obtaining chips. You are well within the price range of selling riverboat chips.