I am using Cricket Wireless 4 lines for $100 now.
I went to buy a cheap HTC phone. If I remember correctly, you can request
bootloader unlock for all HTC phones. I rooted the phone and install WiFi
Tether Router app on the phone. This app is a VPN alike service. It turns
att 4G LTE cellnetwork into a wifi hotspot. This app drains the phone
battery fast.
I handed this phone to my mom and she uses this with her laptop to watch
Netflix. 3Mbps is actually fast enough for her. I am not sure if she's
watching it with 720p or 1080p. She usually use about 60GB~70GB of data per
month on that line.