T-mobile Sony Xperia Z1s Unlock code -where to buy it and how much is it?

My brother got a Xperia Z1s at super price from tmobile with this contract, but he is an iPhone fan so he gave it to me. Only problem I do not use tmobile, so want to unlock this xperia z1s, and would prefer to do it as cheap as posible.Waiting for opinions from people that done it already, please don't just promote your store, real opinions

I unlocked a tmobile Z1 last week, searched a bit for a good solution, as very expensive prices for sony, best solution found was on ebay for 29$ and on an website onlineunlocks.com for 27$, so went with the cheapest option. Seems was a good choice as got the code in 2 days only and on ebay was said could take up to 10 days.Here is the place I bought from