Prices will be vastly different when you want to build the computer. Open a new thread up a day or two before you're actually buying the parts.
Also within you're budget get something like this. I was bored and wanted to see how much a new computer would be. So this is exactly what I'd get. http://pcpartpicker.com/p/jiLp
I picked everything to support the eventual three monitor setup and CF cards I wanted in the future. Unfortunately since I made it the price did jump up $50. If you don't love that case I'd consider this one. http://www.newegg.com/Product/Product.aspx?Item=N82E168...(Computer%20Cases%20-%20ATX%20Form)-_-Zalman%20Tech%20Co.%20%20Ltd-_-11235035&AID=10440897&PID=3938566&SID=