I have a very basic set up a regular fridge, fits two corny kegs sitting in the bottom and the gas bottle on a hump at the back. A pluto gun for each keg, very simple, probably in the vicinity of $400.
I have had a recurring expense of filling gas bottles though. I had a major leak and lost two bottles (6kg each!) in short time. I discovered the gas line was a bit burred where i'd cut it and wasnt sealing in the john guest fitting very well. Since neatening it up things have drastically improved but im still losing gas somewhere. Ive tried soapy water on all joins but have still lost another bottle full of gas! Im considering going to barbed and clamped gas lines, does anyone have any thoughts?
Forgot to mention im also using some smaller kegs 6/9 litre away camping, have been superb in a little esky, although it was cooler weather, am yet to test it in summer.