Editing the shop
In all Server Setups which use in in-game shop GUI, the shop is managed by EconomyShopGUI. It's worth mentioning that EconomyShopGUIhave their own documentation, that you may want to to reference too, you can find that here.
To configure the shop, change items and prices, visit the EconomyShopGUI config files at /plugins/EconomyShopGUI.