My carrier is ATT. I used to chase every opportunity to keep my costs down, including having an island phone. These days I don’t bother, I put everything except one phone in airplane mode, with wi-fi enabled, I use my phone for one reason or another every day, away from my wi-if. It costs me $10/day, with a 10-day cap on charges. I’m on SXM for 21 days, in the middle of my billing cycle, so I pay $10/day for the first 10 days, and the next 11 days are free. It costs me $100 in total, which is less than $5/day, and I’m good with that. If I should happen to need to use a different device away from my wi-if then I just enable a hotspot on my phone and use that - not fast, but free.