Need more info.
How well was it maintained? I don't know what the stinger entails, so does it have gauges assuming its programmed? How does it look? If it looks beaten up with only 210k on it then most likely the maintainence isn't there.
With no maintainence record I'd offer 8k for it and spend the money you were GOING to buy it with to go thru and either have a shop replace the worn parts or do it yourself.