The last PC thread I could find was from 2017, so any help would be appreciated

It's always been a very strange item price wise since you never know when the next gelatin war will pop up, so you can make arguments for the price being much higher or much lower.

If your actively trying to raise funds from a sale, I would probably say 400mil, maybe a bit less. If your actively trying to buy one 600mil isn't unreasonable to pay. If your actively looking to get one, we are also overdue for a war.

If you think about is as paying 50$ vs 75$ worth of CSC, it's not that big of a price difference for something that is relatively scarce and pretty useful.

The thing that works against it is that the people that it is most useful for are the ones that can win it themselves. Although, it's also an irreversible crafting material for 2 weapons and itself.