It's a very nice bike. Honda makes a good product--very cost-efficient, reliable, long-lived. And while I am not a cruiser person I have to admit it's just cute as all get-out.
But the Rebel is not really a good deal. Used ones go for too much money because everyone likes the look. If the money doesn't bother you, then go ahead.
I'm not sure what the MPG is, but a 250 should be somewhere in the 50s or 60s at least. A good, cheap, fun way to get around!