Well I believe you posted this question in the wrong forum so I suggest contacting a mod and asking it to be moved.
My only other suggestion for your $700 PC would be to provide at least some detail about what you need/want to buy. Like are we talking about monitor, keyboard, mouse and speakers or just a tower? Also what games do you play?
Intel Pentium D 805 Smithfield 533MHz FSB LGA 775 Dual Core,EM64T Processor Model BX80551PE2666FN - Retail
Not bad. Would invest a lil more on the mobo so you can take your 805 to the high 3's or low 4's these 805 chipps can do this b/c of their large 20x multiplyer.