You guys think the automotive markup is bad, try the HVAC industry.
The manufacturer sells it to the distributor who marks it up (won't say how much because I'm a distributor) who then sells it to the contractor who often has a markup of 1.7 to 2 times what they purchased it for.
Most of the difference for the HVAC industry, is having to cover the manufactures defects with labour out of your own pocket. When a new part goes bad, we mostly end up eating the labor to change defective parts. Up here it's x2 for stuff 100.00 and cheaper, 1.65 for 100-500, 1.5 for 500 plus. Sometimes the manufacturer won't even warranty their own stuff, especially electronic parts.