public void onEnable(){

        FileConfiguration config = new YamlConfiguration();
        try{
        config.load(this.getDataFolder() +"/Items.yml");
        }catch(Exception e){
            e.printStackTrace();
        }
        List<String> stuff = config.getStringList("");
        for(String s : stuff){

            int i = config.getInt(s + ".price");
            i = i*2;
            config.set(s + ".price", i);

        }

        try{
        config.save(this.getDataFolder() + "/Items.yml");
        }catch(Exception e){
            e.printStackTrace();
        }

    }