Essentials /sell

[DucPro]

How much would it cost to turn Essentials /sell into a GUI, also adding support for multiple ranks? Multiple rank support would be like this: The game auto-detects your group, and when you do /sell, it proceed to sell your items with the said defined group inside the config
Current format: stone: 1.0
What I want:
stone:
A: 1.0
B: 2.0
C: 3.0
How much would something like this cost? I DON'T want any new plugins, just modify the essentials /sell itself.

 

[Brazy]

https://www.spigotmc.org/resources/...that-automatically-sell-quick-sell-gui.28812/
https://www.spigotmc.org/resources/ushop-simple-sell-all-your-items.15491/

 

[DucPro]

https://www.spigotmc.org/resources/▶-autosell-◀-create-chests-that-automatically-sell-quick-sell-gui.28812/
https://www.spigotmc.org/resources/ushop-simple-sell-all-your-items.15491/

True problem is that those both plugins I tried, they don't support numbers that is in the sextillions. Meanwhile, essentials /sell do it perfectly. And also, both of those hook into Vault, which ALSO don't support numbers that big. So yeah, that's why I'm looking for someone to do it INSIDE essentials
(Also: I'm looking for a plugin that supports MULTIPLE-GROUPS)