Bitcoin is tough as nails to get in the USA.
Basically you have to go open a digital wallet (think like Paypal but more hassle since banks don't typically worth with Bitcoin brokers). Throw your money into the Bitcoin exchange who will convert your cash into a Bitcoin. A single bitcoin is worth over $500 so you will purchase enough of a bitcoin to equal $320 (with the company running the wallet taking a commission for the conversion).
You will then go to Newegg, purchase the consloe, enter you wallet information and the bitcoins will get transferred out of your account and into theirs. The problem is that most Bitcoin wallets do not do business with US customers because of US money laundering regulations.
https://coin.mx/
https://coincafe.com/
These accept credit cards but will add a 7% surcharge for doing business. Alternatively you can send money directly to them from your bank through a wire or money order or one of their other options. This is of course risky in the sense that when your money is gone, it is GONE. No refunds EVER. It's a permanent transaction. No chargebacks. No nothing. The deal is done. Hands are shaken. Life goes on.
But at the same time you won't be charged extra other than what it cost to get the money to them. Doing this HOWEVER will result in a certain number of days where you have to wait for the money to be transferred into your account. The sale may very well be over by then. If it's not then you'll have to buy into the Bitcoin stock market (where the value of a Bitcoin - like in a normal stock exchange - will go up and down like a roller coast on a minute by minute, hour by hour basis).
What this means is that you can purchase $400 worth of bitcoin but if in the next five minutes the market crashes you can suddenly find your $400 of bitcoin suddenly devalued by $10, $20, $100, or even $200. You can obviously wait for the market prices to recover in which case you can sell out or make a purchase but the simple truth is that you're buying and selling essentially with stocks rather than cash. This is VERY risky.
Imagine if you were using Circuit City stock to buy and pay for things like Milk, Water, and Food and suddenly the company went out of business. Now your stocks are worth pennies on the dollar you bought them for. That is essentially what can happen with Bitcoin due to the instability of the market and a lack of regulation.
The low price today was $427.60 and the high was $487.28 today. If you bought $487.28 worth of bitcoin at the height of the market today you could very well have ended losing $60 worth of value right away. Enter the market at your own risk. If you have any other questions, I'd be glad to answer them for you.