I don't really patronize any dealers where I am now but in the luxe goods market (which is what "high-end" is), I would always call well in advance to set up an appointment. That process itself was often instructive.
I dealt with many dealers when I lived in NY metro- some good, some bad, some indifferent.
Ironically, one of the best dealers I encountered in my last decade plus in NY was someone who I did business with entirely through house calls-- he brought equipment to audition, did visits to address repairs, brought manufacturers over, etc. It was only when I was in the process of leaving NY that I finally paid him a visit at his facility, which was impressive, but it was more of a social call than anything.
A good dealer is something to be treasured--it isn't just about selling something--long term- the support, the knowledge, the willingness to explore other possibilities beyond what the dealer himself might regularly carry make for longer term relationships.
I've found this to be true in all sorts of endeavors beyond audio. A good dealer will know that the relationship, the referrals, the repeat business, all count, probably more than ever.
Having not set foot in a retail hi-fi store in years, I don't know how much truth this still holds. Most sales people learn how to "qualify" customers pretty quickly. The best "dealers" of any type of good or service will not be rude because you never know....