and what about the customers that actually want to order something >100 ?
if you really worried about fake orders, only accept pre-payment by credit card.
very simple and very effective
furthermore, I believe you are trying to find a solution to a non-exiting problem as I have not heard of one user of wppizza that had this problem as the user has to physically click on things in various places to even be able to add anything , then add order details etc etc – i.e behave like a normal customer