Ax Trade Plugin handles money as well as items. You can sell an item for cash, buy something with cash, or mix the two in a single deal. It also supports multiple types of server currency, so you can trade with exactly the money you want.
Know which currency you're using
Many servers run more than one kind of money, such as a main cash balance plus a second currency. Before trading:
1. Agree with the other player on which currency the deal uses, not just the amount.
2. Check your balance in that currency using your server's usual balance command or menu. Ask staff if you're unsure.
Adding money to the trade
1. Open a trade with the other player the same way you would for items.
2. Look on the trade screen for the option to add money, and choose the currency you agreed on.
3. Enter the amount you are paying.
4. Check the other player's side. Make sure their item or money offer is correct and uses the right currency.
5. Confirm once both sides match the deal.
Avoid currency mix-ups
A common mistake is agreeing on "500" without saying which currency. Always name the currency in chat before you open the trade. Then double-check it on the trade screen before you confirm.