Thanks for the helpful replies everyone, I've been scrounging Ebay for the last hour and managed to find 3 listings which include 4 carbs for around $100.
Downside is that the intake sizing etc etc isn't listed so I will have to wait for the seller to back to me.
I may not buy for another month or so (due to lack of $$), but getting a rough idea of what to look for will help me a lot when it comes to decisions.
These are the ones I am looking at:
http://www.ebay.com.au/itm/3805163515 ... _trksid=p3984.m1423.l2649http://www.ebay.com.au/itm/2810751252 ... _trksid=p3984.m1423.l2649http://www.ebay.com.au/itm/2810754544 ... _trksid=p3984.m1423.l2649