Raise prices - build capacity until you are just not filling the stadium. Then fire the PR guy and recruit a new one with higher or lower skill level. The changes should be due to the quality of the PR manager. Then post your experience here ;-)
My view is to maximise the prices and invest resources rather into players. Once you are at the top of the pricing range, you build up capacity.
Many seats at low prices do make more money than few seats at high prices.