I'm switching from sprint to tmobile?

My bill at sprint is way too high in my opinion for service that isn't even good. My sprint iphone is slow, sometimes my messages don't go threw or come in and I'm just tired of it now i pay $95-$110 a month for 1 phone line unlimited and I'm considering switching to tmobile a few of my friends have it and they never complain & they say it's a good pcs. So I just have a few questions, how much is an unlimited phone line with tmobile? I will be purchasing another iphone (with sprint I have the 4s currently) there's only me on the plan and if anybody has tmobile how much is your bill?

$50 unlimited for one person per month. Also no contract so you can switch service anytime.

I just got the $50/month unlimited plan, too. I really like it so far. The thing with them is that they charge you retail for your phone. So, for example I bought a Galaxy S4, and I pay $25/month for it for 24 months until it is paid off. I can leave T-Mobile any time I want, but I would have to pay off the phone. With some carriers, the phones cost less, but you pay more for service. The advantage with T-Mobile is that if you keep your phone more than 2 years, that extra $25/month charge goes away and you just pay your base rate.

First make sure that your iPhone has SIM card Slot for GSM use.( T-mobile At&t My Simple mobile… Uses the GSM Technologies )

If you do have GSM Version and unlocked iPhone, you are good to move to Tmobile.
I have unlimited T-Mobile plan, call text and web with my iPhone 5.
70 per month + Tax ( I pay just 70.00 i got 10% off from the store manager per month )
( no contract required ).
Ask for employee discount in the store and get 10% discount in your monthly bill.

One line with T-Mobile is $50 a month and that includes unlimited talk, unlimited text and "unlimited" data- you will not pay overages for data, but it does slow down after a certain amount is used unless you pay extra. Even when it slows down it is still very good.