I am aware that the optimum price estimations are sometimes a bit high. This has got various reasons:
1) The price estimation is only an estimation and not 100% correct. It does not take factory sizes of other players into account. If it would, the calculations would take around 10 days if I .
2) Annual costs are read in from the .txt-file. These do increase with higher price (due to increased repair cost), but the calculation works with a constant value. Therefor the estimation will always give you a higher optimum price tag. It will change for next time.
3) The overall price level is set by the competition. If there is no good and cheap competition (especially for the wealthier customers), you can sell them anything at any price.
I will look into it whether fixed price look-up tables work better, although I am not a friend of fixed values.
4) This is only a forum game made by an unexperienced guy in terms of game development (me). For the first round I am happy with how everything worked out. For next round I will adjust some of the magic coefficients and the results will hopefully be a bit better than next time.
And by the way: There will be never be fixed limits like for example "Semi Slicks only" as long as I'm in charge of this challenge.

This makes it way too complicated for a forum game. If you want something like that, play car scenarios. I want my challenge to be like: If I use Semi Slicks, I will automatically sell more cars in the trackday category. And that's totally the way it works.