Thanks to
@Alagesia for providing this suggestion!
With this update, I've added a new configuration option to the
shops.yml file. This option, 'shouldGiveItemOnPurchase' will allow you configure for each item in each shop whether or not the user should receive the item displayed when they purchase it.
If the option is true, the item will receive the item display in their inventory. Otherwise, the item will not be added to their inventory.