You probably should've read my post that followed that one - the one where I said there's nowhere in my bill (VZW but they are all gonna do the same crap) that lists any type of device installment. In other words, there's no "installment" to be reduced/eliminated from my bill if I start paying full price for my phones up front.
I'm also not sure where you are getting math of buying a phone with nothing down. Are you talking about AT&T NEXT? I'm not.
Right now with Verizon I pay $66 out the door including tax and fees for unlimited talk/text and 2GB data. I'm on a 2 year contract with a subsidized device. Nowhere in that bill breakout is there a section for "device installment" that can be reduced or eliminated if I were to have bought the device full price. Also, after two years, I don't believe the price of my monthly bill gets reduced whatsoever, which is why you traditionally are ripping yourself off by keeping a device longer than two years, because to my knowledge nobody's bill ever gets cheaper once their contract is up (it would be suspicious for the "service" portion to just decrease as well), when the supposed "installments" are done and the phone is supposedly "paid off". Nor do I think it's going to be reduced if I start buying the phone full price outright.
I highly, highly, highly doubt that if I buy a device full price, I'm going to have a Verizon plan that is around $40 out the door including tax and fees. This would be the major carrier plan of the century, and I've never seen anyone have that.
Pretty sure whether I buy my device outright or on a two year contract, my service will be $66 a month regardless.