L.L. Bean offers the ExOfficio Men's Ziwa Convertible Pants with Insect Shield in Cigar or Light Khaki bundled with a $10 L.L. Bean Gift Card for $89.99 with free shipping. Assuming you'll use the gift card, that's $20 off list and the lowest total price we could find. They're available in sizes 30 to 44.
Orders placed by December 22 at 12 pm ET are guaranteed for delivery by Christmas.