If you look at it, while they charge less for connectivity they actually charge $10 more for a subsidized phone for 20+GB. This is obviously a ruse to get people into paying $600 for a $300 phone PLUS service. They are hemorrhaging cash flow and need to get people weaned off subsidized devices ASAP. They are on the ropes, no doubt.
Long story short, these prices are a rip and for non-subsidized why wouldn't you just go to a prepaid carrier and pay less. In my state postpaid adds 18% to your bill.
Oh, and that disregards the fact that while my area is "LTE launched", no LTE signal is to be found. But 0.128kbps still works