This forum has already proven helpful to me - thanks to all who read and respond with their ideas and experience. 

Our Sales Head is asking whether we can set up a warning message to flag a sales order that would produce a negative gross margin (loss). 

We already show the most recent and average costs on the sales order screen, and have intentionally chosen not to submit sales orders for approval but understand we could do this.  Simply looking for a way to generate a warning message that must be cleared in order to raise awareness.  Thinking it might be similar to the warning that a customer is X days overdue when entering a new transaction for that customer.