UltraStorage can hook into almost any plugin directly to get the sell prices of items to be able to have auto-sell! If your shop plugin isn't listed below, join the and request it!
ShopGUI+ (recommended) (paid)
EssentialsX (free)
EconomyShopGUI (paid)
CMI (paid)
This page will contain the starting steps on how to download, configure and use UltraStorage