Northern Tool offers the Gravel Gear Men's Zip-Off Nylon Work Pants in Navy or Dark Khaki for $39.99. Coupon code "248527" cuts that to $34.99. With free shipping, that's $30 off list and the lowest total price we could find. They're available in waist sizes from 32 to 42 and inseams from 30 to 34, although not in all size/color combinations.