I home brew and keg as well. Great way to brew and drink beer. I set up with kegs back in 2008, and have spent a minimal amount with it. All bought from
www.craftbrewer.com.au - excellent help from them always too.
From memory costs are:
4 kegs @ $80 each = $320
Regulator twin guage = $120 approx.
Connecting hoses and bits = $25 approx.
Bronco faucet (basic tap) = $15
Setup total = $500 approx.
Then I rent a C02 cylinder from BOC gases for about $50 per quarter.
I got a free fridge from a mate for fermenting, and bought a small one from Good Guys for about $500 that fits two kegs at a time. I only use the most basic Bronco tap, so I didn't have to cut holes in the fridge.