Why not buy a T-Mobile refurb?
What model are you looking at? 2, 3 retina, air? Mini?
Below is the information on what frequencies it uses in the different bands. For example, if the iPad you are looking at supports 1700 MHz and 2100 MHz frequencies of G4 LTE, then it will work on T-Mobiles network.
The 2012 Verizon iPad would also work on ATT on some bands/freqencies as macrumors indicated:
Verizon iPad does indeed work on AT&T's network when equipped with an AT&T micro-SIM and the device's carrier settings are updated to support connecting to AT&T.
Big question on everyone's mind buying the Verizon iPad was whether data from AT&Ts 3G network would work on this iPad, or if Verizon/Apple would block this.
I was one of the first to obtain a Verizon iPad and can happily confirm that this is allowed! I used my ATT iPhone 4S sim card and took out the Verizon sim, and data worked! You must apply the AT&T APN carrier settings before this works though.
It is important to note, however, that a Verizon iPad will be limited to non-LTE bands (EDGE, 3G, HSPA+ 4G) on AT&T. The Verizon iPad hardware supports only the 700 MHz band for LTE to match the carrier's technology, while the GSM version sold for use on AT&T's network supports both the 700 MHz and 2100 MHz bands as used by that carrier.
T-Mobile's advanced 4G LTE network is smoking fast! With incredible speed, you can do more using our nationwide 4G LTE network. Check our 4G LTE markets to see if you're covered.
- T-Mobile’s 4G LTE network uses 1700 MHz and 2100 MHz frequencies. You'll need a phone that supports LTE 1700 MHz and 2100 MHz frequencies. Check Tech Specs to view your phone's capabilities.
- Once you're registered on our 4G LTE network, you can take advantage of incredibly fast download speeds.
- With 4G, theoretical maximum download speeds range from 21 Mbps up to 42 Mbps.
- Our 4G network operates on the 1700 MHz and 2100 MHz frequencies. We use 1700 MHz and 2100 MHz frequencies to use voice and data services. You'll need a phone that supports 1700 MHz and 2100 MHz to connect to our 4G network.
- Once you're registered on our 4G network, you can take advantage of incredibly fast download speeds, and even use voice and data services at the same time.
- With 3G, theoretical maximum download of 14 Mbps.
- Our 3G network operates on the 1700 MHz and 2100 MHz frequencies. You'll need a phone that supports 1700 MHz and 2100 MHz to connect to our 3G network.
- On our 3G network, you can use voice and data services simultaneously.
- EDGE, our enhanced 2G service, delivers a theoretical maximum download speed of 236 kbps.
- GPRS, our 2G service, delivers a theoretical maximum download speed of 114 kbps. Typical speeds are between 35 kbps and 45 kbps.
- Voice and data services cannot work simultaneously when on GPRS or EDGE.
