You aren't going to be able to find one in good condition for such a low price. If i were you, I would save up the extra cash to get one that actually is in good condition. Take into effect you are going to need a good mask, hopper, tank, paint, etc. in order to play. Paintball isn't a cheap sport, if you want to go cheaper, I would really suggest airsoft.
Keep checking ebay. I got one brand new in the box with the wrapper still on it for $100 last year. Although people may not be so quick to get rid of them now the Smart Parts is back in business again.