Would I be able to upgrade to an iPhone 5s?

I have a Samsung Galaxy S 4G and have had it for almost 3 years now. My dad said that we can get an upgrade this month for T-Mobile. I think the iPhone 5s looks pretty cool. Is it possible to get one for an upgrade? If it is, how much would it cost?

There's not much point of you buying a smartphone if you don't know how to use the internet.

http://www.t-mobile.com/...617ab.html