Flagship stores, are almost always 'Loss leaders'. Warner Bros, closed all their stores after a number of years of paying out in operational costs more than they were trading. There are other examples. A high profile store in London's Regent, Oxford St or Knightsbridge for instance probably has a minimum rateable tax value of £50,000 a month before you even think of rent and staffing costs. That's a lot of guitars sales.
Then you'll have to deal with some snotty stuck up sales guy, who actually knows nothing about the product except its perceived iconic status in the marketplace. Hey you may even have to show a Gibson Members Club card to gain entry without appointment. I can see it all!