I just moved to Boost Mobile a couple weeks ago. Got a ZTE Max XL no contract phone for $100. This is new model only out for about a month now. 6" screen, (it's big), 16 gig ROM, 2 gig RAM, huge 4000mah battery. Very happy with it, great screen, very snappy performance with LTE. Boost is on the Sprint network for coverage. I'm on the 3 gig data plan for $30/month. Now they are having another discount of $20, so you can get this phone for just $80 online. Just thought I'd let you know in case anyone is looking.
Another thing I learned in all this is that most of the "no contract" phones, if you buy one from the carrier, the phone is locked to that carrier for some period of time. Typically you have to run up X in billings or be on their no contract plan for a year, before they will unlock it so you can take it to another carrier. Also, while the concept of buying an unlocked phone sounds great, most carriers have limited the specific phones that they will accept on their network. So, you could buy an unlocked phone, which while technically capable of working on a specific carrier's network, ie it's GSM, meets all the tech needs, that carrier still can and often does refuse to allow you to bring it. In other words, there are still plenty of gotchas in the land of no contract phones.