Where are the best places to get decks of cards in Oklahoma City?

If it is standard issue bikes then I would think your Sam's Clubs would be a good place to look for a brick (they might offer a one day pass if not a member). Target and Walmart have good prices on single decks of current USPCC issues. My Walmart often carries a four pack of bikes (2 red/2 black) at a decent prices. The chain pharmacies seem to be more expensive in my neck of the woods (MD).