For a new setup, running a lower power motor, 5k, with decent safety gear.... the higher the HP class, the more $$$$. Also, you need to allow for tires, clutch disks, and broken parts... Starting off, you want have to buy tires as often, but youll be going through clutch disks like they are going out of style from spinning out. My frist season, when I was running jrs, it wound up being about 7k, but since I was so young, my dad picked the tab up, I spent about 500 of my own $$$ on my gear. You can get set up with craftsman tools for well under 100$ buying all new tools(instead of taking out of your tool box) Sae and Metric allen sockets, metric wrenches, pliers, basic stuff... For your second season, your looking at under 2k including motor work and tires, unless you start breaking obscene amounts of parts (everybody gets the bad luck spell though). Money is one thing, but youve got to be willing to spend a decent amount of time at it. People think its just like board walk gokarts, but the truth is, there is a serious possibilty to get seriously hurt. We wear no seatbelts or anything like that, the idea is if you ride up on soembodys tire or roll it in a corner, you get thrown from the kart... not a good situation either way. Also, when you first start out, your toast after a 10 minute track session and ya need to take abreak. People take power steering for granted. Im not mr fitness, but you cant be horribly out of shape either.
If you can find somebody getting out of the sport, you can get thier complete setup for a pretty good price, but dont bother if its been raced more than 2-3 years.
I see your in NJ, Where are you located? If your up far north, ID say check out OVRP.Com (oakland valley race park) Cuddebackville NY.. BEAUTIFUL track with an excellent but very expensive kart shop. Central NJ check out Englishtown
Southern look into Deleware.
If your seriously interested, let me know, I can help you in selecting a class and gear and all that other fun stuff.
Jim