I'd say figure $200 to get into it. that's assuming a new regulator, CO2 tank, and a couple used corny kegs, and basic picnic taps.
Then you gotta chill those kegs some how...
Primary: English Mild
On tap: Pale Ale, Lancelot's Wheat, English Brown Ale, Steam Beer, HoovNuts IPA
Bottled: MOAM, Braggot, Raspberry Melomel, Merlot, Apfelwein, Pyment, Sweet mead, Cabernet
Gal in 2009: 27, Gal in 2010: 34, Gal in 2011: 13, Gal in 2012: 10