The Deal Desk Exception Call

Sales wants non-standard terms for this deal: [THE DEAL SIZE, THE EXCEPTIONS REQUESTED - DISCOUNT, TERMS, LIABILITY, PAYMENT, WHY THEY SAY IT CLOSES THE DEAL]. Make the call: the precedent each exception sets (every deal desk answer becomes the new floor), the real cost of each in dollars or risk, the alternative that gets the rep a win without the precedent, and the conditions under which saying yes is actually right. End with the decision and the one-paragraph answer to the rep that teaches, not just rules.