This study examines the effect of competition on price dispersion and argues that the effect is contingent on the ability of firms to meet market demand. Our comparative static results show that competition among symmetrically capacity-constrained firms leads to a price decrease in the lower tail of the price distribution and a price increase in the upper tail. In contrast, competition among symmetrically capacity-unconstrained firms, or among firms with asymmetric capacities leads to an overall price increase along the distribution function. To investigate these findings empirically, we use a novel data set from the U.S. corn seed industry with farm-firm-level sales information for conventional and genetically modified corn seeds between 2004 - 2009. We estimate the empirical model using the IV Quantile Regression, and found evidence consistent with the above mentioned comparative static results. The analysis also shows that capacity-unconstrained seed firms charge a price premium, confirming the positive relationship between product availability and pricing found in our theoretical model.