Buying Bitcoins in the US is much more difficult than buying hardware. Buying Bitcoins doesn't appeal to me as being fun. Running my own little mining operation is fun for me. As i said, this is a hobby. I'm not in it for the money.
Maybe back in 2011, but not anymore. It's a lot harder to buy hardware these days as they have a very high demand and BTC is available on so many exchanges plus it's easy to get a BTC to PayPal deal on these forums, but nearly impossible to buy mining hardware at a reasonable price.