Imagine if you will this plugin but made so players could use it on vending machines they placed. You could have it so I does a check that the vending machine was placed by the player trying to edit it. You could also do a friends check so team mates could all edit the vending machines.

We use tons of custom plugins and custom items that my players would love to sell to other players. Please please please look into this. Could even be a paid plugin. I'd definitely buy it. 

I would also purchase something like this. 

Not so much the friends access part but being able to list special import items that are skinned or sell/buy items via skin id would be a game changer