I suspect some buyers do not have a good understanding of this.
Example, a set of globe lenses.
There is the cost of the glass and slumping, plus cost of screening.
Plus... the cost of preparing the artwork, burning screens, separating colors, etc, etc. Protoypes, work that needs to be redone, etc..
Anther example that I am more familiar with, a die cast piece.
Is it the cost of casting, plating..or more??
What about the prototype, the first three versions that did not perform as expected, the rework and redesign. The fine tuning of the mold to get a better result.
All this has to be reflected in the retail cost, they are hard costs that will only get absorbed easily if production numbers increase.
As for royalties, this is my opinion only feel free to correct.
I am thinking a royalty paid to use is 10% or under, more often 3-7%. To me that does not sound like a lot, actually a win-win for both parties. Paying a little to sell a lot is a great deal in my view.
Just my 2 cents ....