Acer AM3450 + AMD Radeon HD 6850 + Antec BP550 Plus 550W = ???

Acer are as good a computer company as anyone else .

The FX 4100 in that build is a decent processor , the motherboard uses an 880g chipset so thats OK too , but not ideal

But financially it doesnt make sense once you have also had to buy the graphics card and psu . That must put the total cost over $700 , and you can build a much better gaming computer for that price if you are prepared to assemble it yourself .

The total price is $694.98. I also don't want to build the computer myself, I'd rather just swap out a few parts. So would you say that this is a good build?

No

If you can swap out the psu without removing the motherboard I would be very surprised . Once youve done that you have voided any warranty , and rebuilt the entire computer anyway

Build new , avoid the limitations

Alright would you have any suggestions on what to build? I'm a complete noob when talking about computer parts. I'd like to be using the same graphics card.

Some requirements:
RAM: 6GB DDR3 or higher
500GB or higher
3.0GHz or higher
CPU: i5 or AMD FX or better

I buy from Amazon, Newegg, Frys, TigerDirect.
My budget is $700 or under (preferably under).