My take is this:

We've been down this road before. Flourishing civilization doesn't happen as the result of catering to people trying to menace it and making it harder to contain them-- that's what increasing pearl cost does, makes it harder to contain them. When "the right people" are pearled- the raiders, unjust pearlers, overall menaces (high correlation with currently or formerly banned players, although probably coincidence), civilization has the oxygen to breathe and flourish. When "the wrong people" are pearled, there is more chaos, menacing, and destruction which suffocates civ. There is always going to be a push and pull between creators and destroyers. Sometimes is not so clear cut who is who. That is one of the fundamentals of civ. It is each civs task to navigate that and try to survive. Not all of them will, that's what makes it feel real.

Someone is just as likely to quit if they can't stop someone from perma raiding them because they can't afford to pearl them as they are if the person who is perma raiding gets pearled.

Maybe this is a hot take from an evil perma pearler, but I strongly believe in the original intent of prison pearl which was to allow players to enforce their own rules, regardless of how "good" they were, without needing an admin to step in on their behalf (unless something truly extraordinary happens, which I don't think is the case).

tl;dr I think severely restricting pearls, to an extent that it really matters who you decide to keep pearled, is an amateur way to address the temporary "problem" of "the wrong people" being pearled and creates a long term problem where it's impossible for players to enforce the rules of civilization.

Please share your thoughts on how you feel about pearling and the implications for civilization, and what it means for civilization to be player-driven.

Full disclaimer my civ holds 0 pearls, we have freed everyone we've had to pearl so far with reasonable terms.