Workers!
If you are spectacle of purchasing the plugin, I urge you to look at my other plugins and look at the reviews.
Some extra info: I have seen servers sell ore workers for $50, and a lot of people purchased them. It is a very good resource and you could make a lot of cash from it :)...
Name of the plugin you want : Factions All-In-One
Spigot Link : https://www.spigotmc.org/resources/factions-all-in-one-autofly-chunkbuster-weblimit-flevels-crates-ftop-tntfill-crophoppers.52455/
Price : 15
How it would contribute towards the betterment of the community : Useful for factions...