A gaming machine has a wager-input device for receiving a first wager from a player to play a wagering game having a basic game and a bonus game. A display displays a plurality of symbols located thereon during the basic game. The symbols indicate a randomly-selected outcome selected from a plurality of outcomes in response to the wager. The plurality of outcomes includes a bonus-triggering outcome. A set of available game-enhancement parameters is displayed and the player is provided an option of submitting a second wager to purchase at least one of the set of available game-enhancement parameters. The set of available game-enhancement parameters provides an enhancement selected from the group consisting of: additional bonus-triggering outcomes providing a higher probability of triggering the bonus game, and enhanced awards during the bonus game.