Elite Coins (or whatever you decided to call the Elite Mobs currency as the name is configurable) can only be obtained by fighting mobs, guaranteeing that players can only buy better weapons and armor (frequently the best in the server by a fair margin) through combat. By default it takes a very long grind to be able to afford god-tier armor, and it is fairly easy to lose it, making having top-tier armor something players truly have to work for. In most servers, players are able to trade just about anything for currency. This would mean that by simply going afk for long enough in some form of automated farm, players would be able to quickly gain absurd amounts of currency, allowing them to buy top tier armor for nothing more than just leaving their computer on.
商店系统是这个插件正在构建的系统. It makes people grind through various tiers of loot and mobs for several hours. It allows players to learn about strategies to counter Elite Mob powers, such as arrow invulnerability. Even assuming that you are fine with players buying their way to the top of the armor tier and thereby skipping all progression, you are probably not fine with players constantly dying because they do not understand how Elite Mob powers work. Players are meant to be slowly introduced to how powers work, one power at a time, and not dropped into the highest tier of Elite Mobs where they can have up to 8 powers simultaneously, which makes understand how each one work in useful time pretty much impossible.
So maybe you are fine with players trading in wheat for god tier armor. And maybe you are fine with players dying without understanding why they aren't damaging the elite mob, likely making them rage quit and hate the plugin and your server by extension. But I am not. This plugin is not just for admins, it is for players as well. I usually allow admins to configure Elite Mobs the way they want to (the configuration options are absurdly extensive, after all) even when this probably results in a subpar experience (in my opinion), but this is one thing that I won't budge on. It is almost guaranteed that this would break the progression system and allow players to trade garbage in and I won't suffer complaints about the plugin giving god armor and having unkillable mobs because some admins screwed up their economy.
But I really want vault though I won't do it. I recommend you add vault compatibility yourself, or hire someone to do it for you. This plugin is open source, you are free to create a branch of it that has vault compatibility.