For my realms server, I was trying to figure out how to make players have jobs if they want to purchase anything. I figured out that I could use a combination of an item and a code that only I know.

I chose an emerald for my currency of choice. I took the emerald and gave it a custom name. For a $1 bill the custom name would be: §l§a$1 Token §k1123. The two tags in the beginning act as a cosmetic effect making the text bold and green but the §k creates the jumbled text mode (I don't know its exact name). Then I put a code after that that only I knew. This way when you went to go buy something from a villager it would only use the premade currency of the server.

As shown in the screenshots one job that I have is a lumber worker. Using custom trades (made using the Universal Minecraft Editor) you will give a stack of wood and get a $500 check in return. You would then go to the bank and see the bank teller to turn your check into cash. You can then take that cash and purchase food, building materials, weapons, etc.

If you have any questions or suggestions feel free to comment on this post!