I have a 500. It functions flawlessly. Mine has a smoothbore slug barrel with rifle sights, and I can shoot 2" groups at 50 yds all day with Win Super X 2.75" rifled slugs. It is what it is, and that's not a bad thing.

You can spend more, but you don't need to. I'd try the gun, and assuming it is not beat up, you are getting an OK deal for the cantilevered mount slug barrel/bird barrel combo. I would pay less for the rifled sight barrel/bird barrel combo.