[Fyron]

But they are not. Just made a game with a race that has 110 Maint Apt and 130 Minerals Apt.

HW: 5 mineral miners, on 98% value planet
6664 minerals production

5*800 = 4000
4000*.98 = 3920
30% bonus from pop, 10% from happiness
So, 130+30+10 = 170
70% bonus
3920*1.7=6664
The math leads to the same value generated in-game.

Next I built an escort with 3 supply pods and 6 ion engines I. Minerals cost is 3450.

Base maint would be 3450*.25 = 863
The game has me pay 517 for it.
110 Maint Apt.
So, that makes 15% base maint rate.
3450*.15 = 517.5

Conclusion: seems to be working fine to me.