I just bought a Rapids Kegerator last week through CraigsList. I purchased the kegerator, single tap tower, one half size keg, a 20 lb. and a 5 lb CO2 tank, and the kep hookup for $280. The fridge seems to work fine (it rumbles a little bit) but it seemed to be a decent deal to me becuase of the additional items that came with it.
You might consider doing a little haggling, but its not absolutely necessary.