We study the existence of equilibrium price vector in a supply-demand model taking into account the transaction costs associated with the sale of products. In this model, the demand function is obtained as the solution to the problem of maximizing the utility function under budget constraints, and the supply function is obtained as the solution to the problem of profit maximization given transaction losses on the technology set. We establish sufficient conditions for the existence of equilibrium price vector, which are consequences of some theorems in the theory of covering mappings.