Like someone else said in this thread, the absolute cheapest phones will give you a hard time and will earn you less money. If you have $100, invest wisely and purchase a phone with good solid performance:

1) The Moto G for Verizon ($69.99) is a popular phone around here and has solid reviews from Perk users.

2) The ZTE Z740/A&T Radiant ($70.16) is another solid phone that, in my personal experience with it, works really well with Perk; I've had no issues with it at all.

Another decent phone on Amazon is the Samsung Galaxy Rush ($47.99). It's a bit better than the cheapest phones and a bit worse than the first 2 phones I mentioned.

Now, if you want the cheapest phones on Amazon that can run Perk TV, the Kyocera Hydro ($33.79) and the Samsung Galaxy Centura ($40.36) are options.

OP, I really recommend the ZTE Concord II by Metro PCS. This phone has the most value for the money (yes, you'll have to buy it with a credit/debit card) at only $29! This works just like the Moto G or the Radiant; it's fantastic for Perk TV and you will be impressed with your earnings.

Hope this helps