If you really wanna stay private, wouldn’t it be better to use Monaro? You won’t have to worry about all the limitations of the physical world, and on top of that you’ll get 10% off. It seems like the overall better option compared to mailing cash.

https://mullvad.net/en/blog/2022/5/3/we-now-accept-monero

My main goal as a pirate is getting stuff for free, and I would reckon that the majority of pirates are the same.