The start price for purchasing online Samsung Galaxy S4 with a 16 GB storage capacity is $199, with a 2 year contract, for which you have to pay monthly $20.
If you want my opinion, I say T-Mobile has very well adopted the policy of selling, creating the concept of sales in leasing; basically is a long-term contract, even though T-Mobile is reluctant to use long term contract to not scare buyers with a long-term perspective. The idea is to pay less for the phone or for the car at beggining, but month after month, for one or more years, to pay the remaining value of the phone or the car thus acquired without too much financial effort.
Now, to make a comparison with the competition: until now, it appears that Verizon, AT & T, Sprint, which are the leading operators in the US will have tariff plans less advantageous for buyers than T-Mobile, so my advice is to check first the offers from T-Mobile.