Keep in mind, these guys were "pickers" long before they started doing a TV show. Their M.O. hasn't changed. They are dealers and are looking to make a living. Like anyone else, they want to buy low and sell high. That would be called capitalism. Of course they are going to ask about stock and pricing in advance because it doesn't make sense to travel to a place if you can't make a profit on what you want to buy. But wouldn't you agree that the price given with a phone description is likely going to be negotiated when you can actually see the item?
And, in the industry, the term "reality" just means it isn't tightly scripted in advance. It is a genre like comedy, drama, variety, etc.