This might be a difficult build to complete because of the high Australian prices and my circumstances, but I'm looking at buying a Gaming pc from either PCCaseGear or Mwave (both australian) and I need to use their assembly services because of my circumstances. 825$ would be the absolute maximum budget. I'm looking to play games like BF3 and BF4 at medium to high settings, with the purchase of windows 7 and the fee for them to assemble it leaves about 610$.
have you looked at getting a pc from MSY computers? they have cheaper parts mostly, and can also assemble for you. PC assembly is really easy, there are plenty of online guides, do some research and maybe try it for yourself.