Preventing zero $ orders from invoicing

At sales order entry time we do not always have a valid selling price set up yet.  In order to ensure we reserve stock for the given customer we do enter the order and leave the price at zero.

In between the time the order is received and when we invoice, we typically expect to have a price and refresh the sales order with that price.  This sometimes gets forgotten and our invoice prints with a price of zero.  This then requires a credit and rebill.

To avoid this problem, we looked at the using the Minimum Order Value Hold however I received the following comment from JDE :