for several years now, my backup phone is a Verizon-branded Motorola 2013 Moto X. Although it originally came out on Verizon, I have an Airvoice SIM card on the $10 for 3 months pay-as-you-go plan, that uses the ATT network. It doesnt run as fast as my primary phone- a Samsung Galaxy S7 on Verizon (typically I use 80-90 GB/month on the S7) , but for casual use, the Moto X is plenty capable. On eBay, they currently go for around $50 used with the option to return to seller if not satisfied.