This talk, based on joint work with Sepehr Assadi, George Li, and Ariel Schvartzman, investigates the revenue properties of buy-k incentive-compatible (IC) auctions. A mechanism is buy-k IC if a buyer prefers to purchase one menu item compared to any multi-set of at most k other options from the menu. Thus, buy-k auctions interpolate between the classical buy-one and buy-many mechanisms.