from eBay, and a lot of what Im interested in have the same specs, but different prices etc.

Obviously quality is different, but have posted a couple links of what Ive been looking at.

http://www.ebay.com.au/itm/Intel-Core-i5-2400-3-1GHz-Desktop-Computer-PC-4GB-DDR3-RAM-1TB-1000GB-SAT...

http://www.ebay.com.au/itm/290624467227?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649#ht_13543w...

http://www.ebay.com.au/itm/360377740799?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649#ht_13257w...

Im just interested in a PC that can play media, internet streaming, multi tasking and a little bit of CS Source activity.

So if any Techs or Pros can suggest or steer me in the right direction, would be much appreciated.

Budget is approx $500 - $699.

thanks