Perma Plate is a paint sealant (http://www.permaplate.com/index.php?categoryid=34), it's worth no more then a $50 wash and wax, if they clay or use an aio product (or finishing polish) the job should be no more then $150-200, depending on how well it's done.
I'd do it yourself and save the money, and it'll probably look better! Buy a good wax or sealant (Collinite is great for long lasting waxes, however, I'd stick with a sealant from the likes of Jeff's Werkstatt, Zaino, and the likes.)
You should consider a clear bra for your door edges, hood, bumper, lights, fenders, and mirrors. When this is done, ask for door cups. Some installers throw door edge guards and door handle cups in (which are applied to where your nails would hit the paint) for free.
I hope that helps! :)