[PvK]

Ya, the reason is that your "maintenance" is actually negative production, so the maintenance cost will be in proportion to the amount of points generated by the facility, which is based in large part on the population of the planet. The curve is not as severe as the construction rate curve, though.

And no, limited resources will lead to disaster, because the cultural centers will eat away all of your homeworld's resources... you would need to add a powerful value improvement ability to cultural centers in order for Proportions to work with limited resources. I'll put a warning about that in the next readme file.

PvK