Amazon offers its Prime members Monty Python's Life Of Brian: The Immaculate Edition on Blu-ray for $5.99 with free shipping. (Non-members can spend $49 or more to qualify for free shipping; otherwise, it costs $4.98.) That's the lowest total price we could find by $4. This edition includes commentary by the cast, deleted scenes, and a 110 minute recording of the early screenplay.
Update: Note that this item is temporarily out of stock, but can still be ordered at this price for delivery when available.