L.L.Bean offers its L.L.Bean Women's Old Port Trench Coat in five colors (Nautical Red pictured) for $79.99. Coupon code "LIBERTY" cuts it to $71.99. With free shipping, that's $27 off list and the lowest total price we could find. It's available in misses and petite sizes XS to XL.
Note: It's also available in sizes 1X to 3X for an additional $9 after coupon.