Questions about Classic prison

[Zovichi]

I'd like to learn more about how classic prison works/possibly want to make a classic prison server.

My questions:

How do the mines work?

If you have higher rank, do you get better ores in the mines?

How do price items in the shop(s)?

What does it mean to be "Free"

What is the difference b/w a donor mine and a normal mine?

My discord is here as well: zov#6443

Thanks for reading