"tiered data pricing, based on consumption, is inevitable"
Welcome to the real world. "Unlimited" usage was never real anyway. Either it didn't really mean unlimited, or it was only a short term feature while the connectivity provider was in "customer acquisition" mode. Bandwidth isn't quite free, more bandwidth costs more money. Even to providers such as LLU ISPs (CLECs in the US??) who pretty much own all their own connectivity, more bandwidth still costs more money.