Parts cost vs. total item selling price is always a black art.
Back in the early '70's, I was a salesman in a small but decent audio shop. One of the perks was the discount offered to guys like me by manufacturers - want to know a product better? Buy it for yourself at half the retail price. It was my "after work" job and I never took a penny out of the store, but got quite a few items I still have and love.
One was a speaker we sold for about $300 each. Nothing special, but I liked the sound dispersion because of a second tweeter on the back of the cabinet. We had a pair on display with the grills off, and some inquisitive patron decided to try seeing how much travel the 12" woofer had by just pushing on the cone. We ordered a replacement driver and were amazed when it came in with a billed cost of $4.00!