Not sure you'll find too many of them used, mainly because people hang on to them. I would recommend getting a new youth model remington 870. My dad bought me one of these when I was 12. I eventually outgrew the gun after a couple years so he put a full size stock on it for me. Almost 20 years later I still use it for quail and doves, and even shoot a few ducks with it, and I still love that little gun. I really don't think you can go wrong with one of these. They're pretty cheap too.....
And for rabbit and squirrel you dont need to go far. The wildlife areas around here such as hillsdale, clinton, and lacygne are good bets.