We explore the interactions among firms with increasing returns regulated to break even by pricing with two-part tariffs. We provide conditions for existence and for efficiency of general equilibria with n-firms. This involves finding hookup fees that are voluntarily paid and cover the firms' losses from marginal cost pricing-a problem that because of both substitution and income effects is complicated by multiple firms using two-part tariffs, but that must be solved to ensure the continuity of demands necessary to prove break-even equilibria exist.