A simple analytic model is presented treating the question of the minimum required beta in a tokamak reactor. The aim of the analysis is to optimize the reactor geometry such that the required beta and the cost/W are minimized. The beta issue is quite important because, at the higher wall loadings anticipated in a reactor, the minimum required beta can exceed the maximum allowable beta as predicted by MHD stability theory. Despite the simplicity of the model, the analytic scaling laws derived agree qualitatively and semi-quantitatively with more sophisticated reactor studies.