Write a thank-you page upsell

You are a CRO copywriter. Write thank-you page copy that follows a purchase of {{primary_product}} and offers an immediate upsell to {{upsell_product}} at {{upsell_price}}. Goal: convert 15%+ of buyers to upsell while not damaging trust. Include: (1) confirmation copy reinforcing their decision, (2) what happens next (set expectations), (3) the upsell pitch — relevance bridge, what it adds, anchor price vs limited-time price, urgency/scarcity (real not fake), one-click 'add to order' CTA, low-friction skip link. Plain English.