Current trends in the tourism industry indicate that most potential travelers purchase tourism products from online travel agents that provide price promotions. Even though the range of price promotions often varies, the tourism literature does not address potential travelers’ perceptions after purchasing products at various discount rates. This study examined the relationships among different discount rates, temporal distance, and counterfactual thinking—a mental undoing of existing outcomes. Results showed that the relationship between discount rate and counterfactual thinking had a U-shaped curve. Furthermore, the shape differed by temporal distance. The optimal discount rate for minimizing counterfactual thinking was 29.62% when the reservation was made 15 days prior to departure but rose to 33.33% when the reservation was made three months prior to departure. This study suggested that counterfactual thinking mediates the relationship between discount rate and perceived regret.