Maybe ... but even in that case ... I am pretty sure you can sell an unlocked GSM device for far more than a Verizon one ...
Also, with the new tmobile payment plans, once paid .. my rates drop. On Verizon/AT&T you continue to pay. Also note that the difference between tmobile and others might be minimal for the absolute high-end phone ... but for cheaper phones ... you pay a lot lot more ...
As an example, even for the cheapest phone (say free) you will pay a minimum of $480 on VZW/ATT (assuming $20pm for 2 yrs) ... but om tmobile, I can get a Nexus 4 (definitely better than most other phones) for $300 and be done ... or even get a Samsung S2 for $265 (
amazon) ....
The best thing to do on Verizon and AT&T is to get the most expensive phone ... and maybe cancel and pay the ETF ... which means the best option is to be a bigger scumbag than they are ... I do not like that ... I prefer the honest option ...
Most new Verizon 4GLTE phones come factory sim unlocked(some older phones were unlocked via update). I don't know about the resell since I usually give my old phones to friends or family to use, and I know it works on AT&T, T-Mo, and other gsm carriers, both domestic and international, without any additional unlocking of the sim required (i have heard some need to be rooted to change the apn to get data, not sure, haven't personally tried).
The Nexus 7 does work on Verizon 4GLTE (no CDMA on it though). Next year, once verizon implements volte, then there's a chance that a nexus phone would work on Verizon. I heard that the nexus 4 *might* work on Verizon 4GLTE where Band 4 has been deployed (it is still in the testing phase) with the original software, and may require some hacking.
With that aside, talking about the price now, I pay $140 (before taxes, fees, and discounts) for 5 lines of service with 2 smartphones, one with unlimited unthrottled 4GLTE. When I looked at T-Mo plans, it didn't seem like I would be saving anywhere close to $100+ ($20 subsidy per line x 5). In fact, Verizon's subsidized rate is close to what T-Mo unsubsidized rate is comparing postpaid plans, making Verizon way cheaper, for my uses. I have the 550 minute family plan, with unlimited mobile to mobile and unlimited night and weekend. Rarely do I even get over 300 minutes peak (i use lots of m2m and n&w which doesn't count toward peak usage quota) on my family's usage. In all fairness, my plan is a legacy plan, not currently offered for new accounts, but if someone really wanted it, they could assume liability of an unlimited data line and add a line to make it a family plan, if so desired. The AoL process doesn't cost anything, but you may have to pay for the donor account. My uses are certainly not a typical usage, and in most cases, T-Mo would be cheaper. but in my specific case, it is not.
With regards to phone prices, there are sales on phones from time to time. I got my Note 2 when it was $50 on contract back in February. There was a $50 money maker deal on the DNA a few months ago (get paid $50 to take it). While not the latest device, it is quad core, 5", 1080p, and imo, a great price based on the specs. The Nexus 4 is way too small for my uses, but if it works for you, certainly a good deal. The subsidy on Verizon/AT&T are already built in, so the $140 I pay for my 5 lines, less the $100 ($20pm as per your post above x 5) would mean that I am paying $40 on Verizon compared to T-Mo plan which would run me way more. Granted T-Mo does offer more, but on stuff I don't need.