On top of that, I'm looking for the Steam Version.
Civ 5 is a Steamworks game, which means no matter where or how you get it, you have to use Steam to play it. If the copy is a physical CD then you have to enter your CD key into Steam. If it's a 3rd party digital copy, you still have to activate it on Steam.
That said, I can gift it to you for 4 BTC.
I've already got an offer of 3 btc, which I still think is too high.