I think kegconnection.com has a sale right now.
As far as a regulator, I used to have two primary regulators, but I found that I wasn't really using them for serving at different pressures (and it took up more room in the kegerator) so I gave that to a friend and went back to one primary regulator that feeds 5 kegs. You only "need" two primary regulators if you want to serve one beer at a higher pressure than another, or something like soda that needs 30 psi while the beer needs 12 psi.
I have one primary regulator with a WYE fitting. One of the ends goes into my 4-way distributor, and one is by itself, to use with my beergun or to give a shot of c02 to a keg after I've kegged it.
How many kegs are you planning on having, and do you need different pressures? That will help you decide what you'd like to get.