To answer your original question further. You can buy 200Gh/s for about $600 if you get a BitMain S1. I wouldn't spend much more than $3/Ghash. If you're new though, I'd consider just buying some Antminers from the group buys section, or sign up on cex.io. Either one will end up costing you about $10/Ghash.
If you don't have any BTC yet and need to, you can buy it on CoinBase:
http://coinbase.com/?r=5295695b9b914d77600000e6&utm_campaign=user-referral&src=referral-link
Cex.io:
http://cex.io/r/0/Raptor2213/0/