I want to maximize the bang for my buck. BioShock 2 had the "Vending Expert" gene tonic, which lowered vending machine prices. Does BioShock Infinite have anything similar?
There is a single Discount Dollar Bill machine in the courtyard of the Hall of Heroes that sells a pistol clip upgrade for half the price (side note: buying this upgrade does not affect the Scavenger Hunt achievement). Other than that, you are out of luck.
Using Possession on a vending machine causes it to drop a small amount of money but the prices remain the same.