What is the average dealer mark up?

mc is ballpark correct. When I had my store I paid approx: 40% off retail PLUS shipping for components for one at a time. Small additional discounts where available with the purchase of multiple units. With cables and other tweeks, up to 60% off was the norm, again with modest discounts for larger orders. All varied a bit with the different companies and sales reps. mc is also correct about companies requiring minimum purchases for the whole line up to be able to carry the line. This, for me was a deal breaker, too mush initial investment. The old saying is true: "If you want to make a million dollars in audio, start with 2 million".

For hardware around 60%, but for accessories up to 90%.

I have never seen 90% off and rarely 60% off.

Typical discount is 40% with some up to 60% off mostly on accessories.  But in the past 5 years things have changed to 50% or less with 40% being the standard.

Happy Listening.  

As a salesman, I once ran into a guy who told me “if it ain’t keystone, it ain’t .” Huh? I learned that meant he wanted to mark up 100% so he needed to buy at a 50% discount. I also learned about “turn,”
meaning how many units were you selling per year. And floor space, meaning how many $$ per square foot were you turning. That’s how good retailers think. Retail is tough, and if you don’t have volume to support inventory it’s even tougher. Manufacturers have it tough too. You want to be able to support your suggested retail pricing and if you have a outlier retailer selling mail
order under that price, you risk cheapening your brand. Anyone who hasn’t operated in this arena likely has no idea.

numbers from above are largely correct, but like the fiances of car dealers, it gets more complicated.  most dealer cost sheets will have the 60% (40% discount) as the baseline.  But then there will be a few more points for larger orders, and occasional incentives to move stuff.  The first unit, to be a floor demo model, and maybe loaned out repeatedly, may garner an additional 10%. There may be cooperative advertising allowances.  And of course, some dealers will modestly discount especially in a package.  Its a lot of money, but as noted, there are a lot of costs to retail in a low volume business -- and we can be a demanding lot.  And as also noted, most manufacturers work on 5+X parts --> retail or maybe 4X parts + labor (which is a bigger proportion in small volume, weird component high end compared to a mass market product that can be efficiently produced by automated SMD lines,and stuffed into a blow-mold box.
Think direct sales is the answer?  Now the manufacturer needs to cover hand-=holding, free in-home demos and the depreciation of "used" equipment, more advertizing, etc.  It saves less than you might imagine.
The value from dealers, if they truly help you sort through alternatives and find the component that a) YOU like and b) delivers high value, is very, very significant.
G

The dealers markup is between 40-50% depending on the company,and international distributors get 55-60% 
i was a dealer for 10 years this is the average.