kegging costs... plain and simple, although most fail to mention that, but you have no way around a regulator, co2 cylinder, beverage and gas tubing, disconnects, a faucet of some kind etc.....
It adds up, although I'm sure with much work, waiting, and frustration, you may find something on craigslist (which in my area has been totally worthless for kegging gear).
So, after all that, the 150 or so that somewhere like NB or Midwest etc. wants for a single keg setup really isn't that bad. Take the plunge, you'll love it.