How much of your car is the dealer covering for $2K? If they are doing the entire car, that would be the deal of the century (obviously, this is not the case). It's impossible to answer your question without knowing what degree of coverage this price includes.

I have never heard of Protex. My car is at my PPF guy at this very moment, having PPF applied to its entirety. I wouldn't use anything other than XPel Ultimate - it is amazing - the reflectivity is excellent, very little orange peel, and best of all, it is self-healing, for smaller scratches.

I wouldn't have the dealer do any PPF - in the vast majority of cases, they outsource it anyway, and upcharge you accordingly. If they do it in-house, inevitably, it will be a sub-par installation. My advice would be to find an excellent independent installer who uses XPel Ultimate, and get them to do it.