Commander Mick : Youre getting ripped off terribly by Harvey norman. They are sitting behind the counter rubbing their hands together and grinning like idiots.
Spend NO MORE than $2000AUD If you are spending more than this, you are being ripped off and wasting money.
From scorptech in melbournce (I live in victoria, I've just bought from them but have no other affiliation at all).
I bought
Asus Gryphon Z87
Intel i7 - 4770
32 G Corsair RAM
Gigabyte R9 280X
all up it came to $1425 (But I already had a case, Power Supply and hard drives & DVD drive)
You can cut out nearly $500 by going for 8G RAM and a i5 4670. You won't notice the difference in performance. I bought what I did because I'm an IT enthusiast and I had a healthy ATO return in my hand. If you don't know what the benefits of an i7 are, you don't need them.
You then also need
a hard drive (about $100) OR
a SSD at about $200
A case and a PSU. Get a decent 550 - 600w PSU.
A DVD rom is also a possible requirement for you. But they run around $20 - $40.
Look at these options and see how much Harvey Norman are ripping you off.
http://www.scorptec.com.au/systems/all/
You can also buy from
www.auspc.com.au (I've bought from them in the past, had no issues).
As a test, I went and specced up a good system for you from Scorptech.
ASUS - GRYPHON Z87 $185.00
Corsair - CMP8GX3M2A1600C9 Corsair 8GB (2x4GB), PC3-12800 (1600MHz) DDR3,$135.00
Intel - BX80646I54670 Intel Core i5 4670 $255.00
Gigabyte - GV-R928XOC-3GD $399.00
Antec - SOLOII $155.00
Corsair Corsair 600W CX600M ATX Power Supply, $109.00
Samsung - MZ-7TD250BW Samsung 250GB SSD, 840 Series, $189.00
Windows 8.1 $169
Total : $1,596 + Shipping.
You need a monitor as well. Maybe $400 for a 27" dell 1920x1080
That would play any new game extremely well.
Anything more is overkill.