My wife and I both had samsung s6's that were about 3 years old and were on their last leg. Had verizon with great coverage wherever we go from Charlotte to mountains, to beach, to rural eastern NC. If I could have gotten the same phone brand new again and for cheap, I would have. But we needed reliable phones and were looking to cut monthly expenses where we could.
We ended up going with Google's project Fi (fi.google.com). A buddy on facebook had a referral link that would get us both a credit (mine is
Get $20 when you start a phone plan with Google's Project Fi just in case) Google uses Sprint, T-Mobile and US Cellular towers for coverage, and whichever one will give you the best signal wherever you happen to be, it uses that one.
Because only certain phones work with it (android phones) and we needed new ones, we got 2 new pixel 2's (which also got us more account credits). They are pretty decent, not quite as good as samsung/iphone IMO, but upper teir. One thing I liked was that with Fi, data costs $10/GB up to $60 for individual plans or $100 for 2 users and so on. If you use 3.2GB, you get charged $32. Unlimited Talk and text is $20, extra person is $15.
Based on our past data usage history, and with 2 phone payments, on average, we should stay around or just below what we were paying for our verizon plan with no phone payment. Coverage is pretty decent so far, not quite as good as verizon, but ymmv.
Our fixed costs on the plan total about $100:
Calls & texts 2 people, $20 + $15/member: $35.00
Device payment: $27.04
Device payment: $27.04
Device protection Pixel 2 (2 at $5/device): $10.00
and the most our data will ever cost is $100 bucks. 3 months in and we are still getting credits for stuff and we haven't had one over $89 yet. Hope this didn't sound like a commercial, but our recent experience is so far so good.