The reasons these dupes happen is because you are not making sure that you have the item in the inventory!!
You can make a cheat client act as if it pressed High alch on a armadyl godsword EVEBNTHOUGH you don't have anything in your inventory.
To fix this its actually quite simple. You make your server check the correct slot and if that slot contains the item id. If so, then do gfx, remove the item, add money.








