I think you got some very good suggestions considering your budget. There certainly are locations where an open frame, non-inverter genset can be used, but the average campground is not one of them. I have an open frame contractor genset for my house and I can tell you it is some kinda loud. For camping I bit the bullet and got a quiet inverter generator. As several have mentioned, Champion has some moderately priced inverter generators that are "campground friendly". When comparing noise ratings keep in mind that a 3db increase equates to twice as loud.