The cost can be tied to the number of nobles or noble points that your
faction currently has. If you lose a bunch of nobles and noble points,
then rebuilding becomes cheap again.
> Or a third option. A faction with 20 active NPs cannot issue FORM.
This is an interesting option, but in this form would restrict
magic-using factions to fewer nobles than non-magic factions. However,
if it was instead phrased as "factions with more than X nobles cannot
issue FORM", then it would foster increased magic use by all the older