Its not the best code but its also not the worst ;)
Check it on SpigotMC: https://www.spigotmc.org/resources/citybuild-ultra-best-free-citybuild-plugin-%E2%9C%94%EF%B8%8F-opensource-and-economy-system.94522/
CityBuildUltra is a 100% configurable plugin you can set every single permission, sound, pitch, message there is, since it is also open source you can customize it to your liking. A Config.yml would be much too big so I decided to make a separate .YML for each command or event. As you can see here: The plugin has a money system with pay command and admin commands, for this it needs a MySQL database. A scoreboard is not included but can be easily programmed with API access. With the money system I made a small mistake, transfers or /money commands take a bit until they are displayed in the chat, because the plugin reinitializes the MySQL each time. A quick docu about the API will be available in the next days. Why I don't update the plugin? I will not add anything more than bugfixes to this plugin. There must be some security systems built into the code that I forgot to remove. These should serve to protect the plugin from modification. But since it is now free this is no longer necessary.