Amazon offers Prime members the Watchmen Collector's Edition: Ultimate Cut on Blu-ray with Graphic Novel for $32.49 with free shipping. (Non-members can spend $49 or more to qualify for free shipping; otherwise, shipping adds $4.98.) That's the lowest total price we could find by $18. This 4-disc set includes loads of special features and the graphic novel.

Note that this item is currently out of stock, however it can still be ordered at this price for delivery when available.