I'm not disagreeing, Shayne, but why do you say that? Personal experience? Heard a war story?
They are a broker who does some negotiating for you with a dealer in your area, receiving a fee for their efforts. You can readily do as well yourself, but some folks shudder at the thought of "doing the dance" at a dealership. And RV dealerships can be worse than car dealers, especially if you are new to RVs and easily baffled with sale mumbo-jumbo loaded with strange RV terms. So maybe they are a help to some folks. Maybe.
As for getting you a better quality rig or any further help in the process, e.g. post sales, forget it. If you can get a quote through them without a fee obligation, you might compare it to what you can get on your own. I suspect you can do better on your own if you shop around, but if you want to buy locally and don't wantt hassle, they can probably get halfway decent deal for you. But anybody can get 10% or more off a new Rv, pretty much just by asking for it. Or going to an Rv show. If they can't get you 15%-20% or more (after allowing for their fee), don't bother with them.