Let the hive mind of Engadget get that for you.
"As someone who doesn't reside in the USA, I was wondering what would be the best way to get internet for my computer in the US for a couple of weeks? If it were Europe I know I'd look for some prepaid data. Is there anything similar offered by American carriers? A MiFi or a data SIM that I can tether from would work, but I'm trying to maintain a tight budget. Help!"
http://www.sensics.com/products/pisight.php
Don't like how they don't have pricing. They suggest you price it. It's kind of like high end sports cars. If you have to ask, it's too much.
"Price
Feel free to tell us how much do you expect to pay, and we can often present to you several HMD configurations in this price range."