As we learned from the last FCC auction, mobile spectrum is expensive. Really expensive. Verizon and AT&T walked away with $20 billion worth of spectrum, while Dish quietly snapped up another $13 billion. T-Mobile was surprisingly quiet, but noted a bit later on they were planning to wait for low-band spectrum to come available via the next FCC auction. Rather than buy spectrum, they’re planning to use unregulated spectrum typically used for WiFi.