The recent framework for tiered spectrum sharing in the 3.5 GHz band allows for environmental sensing capability (ESC) operators to measure spectrum occupancy so as to enable commercial use of this spectrum when incumbent users are not present. Motivated by this, we consider a scenario in which two spectrum access (SA) firms seek to access a spectrum band for secondary access and must in turn purchase spectrum measurements from one of the two ESCs. Each SA has an exclusive licensed access to a spectrum band. Given the purchased measurements, the SAs compete on price to serve customers. We study how the ESCs’ cost of obtaining the spectrum measurement, the ESC’s prices, and the quality of the spectrum measurements impact the resulting market equilibrium between the SAs. In particular, we show that when the ESCs offer different qualities, the only equilibria that can exist are when both SAs purchase measurements from the same ESC.