I get good discounts at the stores I regularly do business with 10-15%--and continue to do business with them. I rarely pay list except for small ticket items and very rare items (like Camac connectors for Levinson amps--and they are ridiculously expensive--I should have asked on Audiogon where to get them at a discount). First time purchasers buying one item that is not priced in the stratospher will frequently not get a discount--depends on the dealer of course. For multiple items, my opinion, you should always get a discount. The % varies depending on number of items, price, dealer margin, and competition in the area.
It might be interesting to note that margins for speakers are in general the highest, some greater than 50%. This of course is not true of all speakers--but most. Also, you may not be aware that some lines of equipment have discount caps, meaning the dealer is not permitted to discount that product more than x% (or they will lose their dealership). Martin Logan does this and the cap is 10%. This is because there are cities with several Martin Logan dealers--and they do not want the dealers competing on price. Of course if you are bundling a package, you can take a larger discount off another item. There are some manufacturers that allow for dealers to accept mail orders and some do not. If you have a dealer in your area that does do mail order on a product you are interested in, chances are he can sell it for less because he typically competes on price with the mail order market and he gets better volume discounts from the manufacturer. I have done quite a bit of business with one such company in New York. They have a nice showroom, very knowledgable people, good discounts, everything you could want. I still do business with them, even though I no longer live close enough to go to their showroom anymore.