Two thoughts: one -- even if the markup is high, some of that still has to go into cost of doing business. With high end equipment, there can be a lot of breaks between sales.
OTOH, high end gear has different criteria for "doing what it advertises" than consumer-grade gear. I can't tell you how many times I've heard the advice, "what works for me in my system may not work for you in your system -- audition!" I need to be able to burn in a piece of gear and then have some dedicated listening time before I know whether or not I want to keep something. Only a local dealer can provide that service, and if he won't provide that service, then he's providing a disservice.
OTOH, high end gear has different criteria for "doing what it advertises" than consumer-grade gear. I can't tell you how many times I've heard the advice, "what works for me in my system may not work for you in your system -- audition!" I need to be able to burn in a piece of gear and then have some dedicated listening time before I know whether or not I want to keep something. Only a local dealer can provide that service, and if he won't provide that service, then he's providing a disservice.