Win probability estimation model that statistically computes the probability of winning a bid at a given price, and profit optimization models that compute the optimal price for a bid balancing the probability of winning a bid at a price with the profitability of the bid at the given price. In one stage, an expected profit margin of a product may be formulated as a function of its profit margin and win probability to compute its optimal profit margin. In another stage, an expected profit for one or more product accessories may be formulated as a function of the profit margin and their conditional win probability given the server win to compute their optimal profit margins. The conditional win probabilities for the product accessories may be modeled as a function of the utilities of the various purchase options that contain the product and that accessory.