[douglas]

Asteroids have a different maximum. The bug is that the planet maximum is checked instead of the asteroid maximum when an asteroid field loses value due to remote mining.

A separate problem is that the planet maximum is not checked when asteroids are converted to a planet, so it is possible for artificially created planets to have values above the limit. Whether the bug here is that the planet initially retains the high value or that it drops later when remote mined or affected by a VIP is a matter of personal opinion.