Trying to help someone find a good phone + plan for her upgrade

So I'm trying to help someone upgrade from a Sensation 4G on T-Mobile, and I was wondering if you guys would know any good routes for her to take.

First off, the basics:

  • currently on T-Mo prepaid. does not want to spend more than $50/mo (before taxes, but after taxes would be better) $70 after taxes is the absolute max, but would like to avoid that if possible
  • no contract preferred, but will consider it if she can get a good phone and still pay the amount she pays monthly now
  • would like LTE, but does not want to spend more than $250 (not too fond of tech, so not willing to pay out the nose for a no-contract phone, but needs good internet)
  • really likes the features of iPhone 5S/5C and the Nexus 5, but are out of her budget range
  • would like faster internet, but doesn't need more than 2GB/mo

the Moto G would have been the perfect solution for her, if not for the fact that it didn't have 4G/LTE. I'm wondering if the next iteration will? Who knows? the Sensation 4G is dying a slow death with screen problems, buttons not working, performance problems with Android 4.0.3, etc.

essentially, I'd like to find her a worthy Moto G alternative with LTE while keeping to her budget. if she can obtain an iPhone or Nexus 5 for $199 and still maintain her $50/mo plan, that would be perfect, but I have no idea if that's even a possibility.

I thought maybe Sprint or T-Mo might have some sort of $30 voice/sms plan with a $20 2GB/mo add-on, but it doesn't look like they do?

anyone have any suggestions?