Though T-Mobile is not the first to begin with pre orders for the Galaxy S5, as AT&T and US Cellular were the first. But yet the device would on all carriers will be available by April 11. T-Mobile offers the device with zero down payment and you would have to pay 24 months of $27.50, which sums up to $660.
Also the price of T-Mobile is about ten bucks higher than that of AT&T. But still it is a good deal as you would not have to sign up a new contract for two years. Also if you order Galaxy S5 from T-Mobile you would be getting a $120 discount on Galaxy Tab 3. You can order it from the link below.