ign celo idea it would be a give command that allows you to give the items in your inv to people who buy them it would also make it easy to do scam reports on trades since if you give a item to some one and there is no pay mods could easily check examp of commands /give < item > < amount > <name> /give hand <name> or if your selling a hole inv worth /give all <name>
The problem with this is that the server command to give someone items (hacked in) is also/give. Maybe try a different command? Also, there should be a message for the recieving person saying something like "You just got <amount of item> <itemname> from <username>!
Perhaps have /trade <player> <amount> <item> <price> Then the player who is buying has a prompt of whether or not to purchase it which would say... "<player> wants to trade <amount> <item> for <price>. Do you accept? Yes or No (perhaps /trade <player> Yes or No). If they accept the money is taken out of their account and the item is transfered to their inventory. (Would also need a check to see if the inventory was full). If they decline then nothing happens. Would in theory eliminate the possibility of scams altogether.