While I was creating a loot chest for a treasure hunt within my town, I thought to myself, "Hm, it'd be nice to be able to put some cash into these loot chests."
There's this plugin called Banknotes where you withdraw a certain amount from your balance and it converts it into a piece of paper with X amount of money on it. You'd right click it to claim the money. Later on down the road when more player events are hosted, this plugin would come in extremely handy. Instead of the creator paying the player directly, he/she could leave a money note in a loot chest. Although /pay exists, the money note would increase the roleplay aspect of the server allowing for more variety of payments and rewards.
My selling point here is that it increases the roleplay aspect of the server and that it adds in a new addition to the economy system.
Link to plugin: https://www.spigotmc.org/resources/banknotes.3200/