The Traveling Purchaser Problem serves as a model for a multitude of transportation and procurement issues. In the basic model, a decision-maker buys products from different markets while balancing the prices of each market together with the tour costs from visiting them. One variant that has not been investigated yet describes the problem of additional tariffs payable when a truck enters a particular area to visit markets. This case describes the real-world situation as it is often found, e.g., near country borders. A subset of markets shares an extra fee as soon as one of them is visited. This paper explores this new variant with zone-based tariffs. The model is set up and then examined in detail to understand the particular characteristics of the problem compared to the basic variant. Furthermore, the structure of the solutions is examined to gain deeper insight into this design.