Not sure if this is even doable or if enough people would use it to make it worth implementing, but having an option for commands to increase (maybe by a set percentage) each time they're purchased would be cool. For example, on my server I let people buy day or buy night, basically purchasing a command that sets the server time. But having it be cheaper at wipe and progressively get more expensive as the wipe goes on would be nice and help it from being used constantly.