Ok, wow, Um, Look at Newegg and zipzoomfly for better prices, also Zipzoomfly has Free shipping on most products.
For harddrive Look for Seagate or western digital SATA2 w/16 MB Cache.
As for the power supply, if you want something flashy and modular that is also a quality power supply then you will have to spend more then 80 Bucks.
Quality PSU for less then 80
If you can find the Blue Gears sound card its worth the 70 or 80 Bucks.
If your going to game then I suggest AMD Dual Cores since the prices just droped.