I wasn't trying to provide a comprehensive mobile services price comparison, I simply chose a service I knew to have comparable terms across the 4 national carriers that own their own towers. MetroPCS and Clear both provide significantly different services being online only in certain metros.

I had skipped handset service because when fully loaded they have service tiers that make it difficult to do direct comparisons, probably intentionally. However:

AT&T unlimited voice: $69.99/mo

Verizon unlimited voice: $69.99/mo

T-mobile unlimited voice: $59.99/mo

Sprint 900 minutes (max): $59.99/mo

and:

AT&T ala carte SMS: $0.20 per

Verizon ala carte SMS: $0.20 per

T-mobile ala carte SMS: $0.20 per

Sprint ala carte SMS: $0.20 per

Considering the radically different cost basis of the two programs it's hard to believe there isn't some de-facto price coordination going on.