Sorry, but it doesn't make sense that you "always" get a 20% profit. If you increase your price, you are not paying for more marketing or more bullshit. You are increasing the selling price, period. And somehow, you are increasing the manufacturing cost, which suddenly evaporates (the money, I mean).
Margin of profit is what you should be able to control.
Sell at a loss for whatever reason or sell stupidly expensive to great profit. If your customers are happy overpaying (Apple model, basically), your win, their win.
A more sensible approach, probably, should be:
- Fixed cost of developing the engine on each race (for instance, 300k) or variable depending on the number of engine points you have
- Fixed cost of producing each engine (for instance, 100k per engine).
- Control the margin of profit OR the total fixed price of each engine.
This way, if you are only providing for yourself, you end up paying up, if you have 2 cars, 500k (same than the default providers), and if you have customers, can charge whatever you want.
If you charge, let's say, 350k per engine to your customer, that means that they are paying for their engines and yours. That's a pro of having a customer. They can also decide that for that price they can become a manufacturer themselves, so that's a risk.
I mean, this is the first iteration of a new system. I am not saying is terrible, I am saying I see room for improvement and that part of the logic is a bit "meh".
Right now the system is: You pay 750 for developing the engine and building 1 or 2 engines, depending on the league. And then, somehow, building those engines for your customers cost between 200k and 400k EACH engine (at which point, building two engines for them is somehow more expensive than building two engines + developing it for you). This is just not logic.
I am not trying to find a "fair" model, as life is not fair, but a logic one. And the actual one lacks logic.