The engine COST (the builder's cost of production) is a closely-guarded secret, and varies from year to year as production improvements & simplifications are made.
The PRICE it sells for depends on how much money the maker thinks he can make in spare parts sales (that's where the real profit is) over the life of the engine. If it's a big customer, the engines may go for less than cost!
So basically it's the same business as Schick or Gillette; give the razors away, make money on the blades...
