Decided to do the math at AT&T... (all prices before any corp discounts, etc)
To give you an idea, we may use 1500ish total minutes a month, mostly mobile to mobile and mostly between the 2 lines (so we will rarely use the any time minutes on any of the big 3). I constantly use 2+ gigs of data, the wife is usually under 1 gig. So I do understand these numbers won't shake out for everyone, but this is why we will be going where the phone(s) we want are (and we can get the best corp discount). Sprint has most likely lost us with the $10 per line charge.
2 lines (did the 550 minutes, plenty with unlimited mobile to mobile), 2 gigs data for the wife (more than she needs), 4 gigs for me (I could use wifi way more than I do, so I could probably save $20 and drop this to 2 gigs), unlimited texting... 179.97
2 lines 700 minutes, currently unlimited data (we will see how their tiers shake out).. 173.95
2 lines 1500 minutes ... with new $10 per line fee will be 170.09