You must understand one - two things... The cost to manufacture something is not the same thing with how much must a company make for it to still be profitable to run.
You can never expect something to be sold without making a gain for a company, or else people who own it will just sell their actions and invest in something else.
Costs... Marketing is a cost. RD is a cost. Packaging and designing is a cost. Graphic elements are costs. Everything is a cost to a company, and the unitary cost of each piece is not really relevant, as much as their value is.
I am honest, if audio companies weren;t making or expecting to make some profit, the laws of business state that they'd simply move to another business, good things are supposed to cost a ton. Does Samsung note8 really cost 1000 EUR to make, when Xiaomi Mi Max 2 costs barely 250$? It doesn't matter how much something costs, what matters is how well it performs relative to that cost, relative to what people are willing to pay for, relative to how other things perform.
Simple scenario: If HD650 were priced 1000$, with every other headphone staying at the same price, would they still sell? Probably, but the numbers would be much lower. If they were 200$ instead of their actual price, would they sell? Probably, not not that probably to sell that many more pieces, price is defined by only one thing, the meeting of the demand and offer, nothing else. You can't impose a price to someone, you can't tell someone what to do, offer and demand.
This is the backbone of what defines the value of something. Whilst keeping this in mind, you can always vote with your wallet if you dislike a price or if something doesn't have the relative value to you...