Who Is Really Doing The Picking?
If you believe only what you see from the show, the pickers are strictly Mike and Frank, as well as other cast members from time to time. That’s not at all what happens in reality, however. The real pickers are the producers, who find the items worth picking before Mike or Frank even ever show up.
As noted before, the prices are agreed upon before the hosts appear. The haggling happens off-screen, with the producers. When Mike or Frank show up, the bargaining that you see is mostly for show — the “final price” that the hosts and the guests agree on has already been decided.