Alienware is overpriced for the parts. Sure, it can run stuff decently, but another computer can easily cost less for the same specs. Also, Alienware has incredibly poor cooling. I've seen stories of people having their cases literally begin to melt because of how hot it got.
Macs are even more overpriced than Alienware.
As for the OP, try getting a laptop with an A10 processor. Its APU will more than likely perform better in most general games. It won't be amazing by any means, but its integrated graphics runs better than integrated Intel graphics. You'll lose some processing power compared to an i5, but since you want to play games on it, it'll overall perform better for that price range.
I'm not entirely sure how to change currency on Amazon, but 700 AUD is equivalent to about 500 USD and this is 450 USD so it's within your price range.
http://www.amazon.com/X550ZA-WB11-15-6- ... a10+laptop
