Very good price that is.
I'd have bought that if I hadn't got fed up of waiting for them to release the set and just bought the first 2.
It didn't take them (and others) long to sell the Rambo boxset at less than 18 quid. Besides I don't have a BD player so I can afford to wait.
Hardly a surprise, Amazon have responded:
Batman - The Motion Picture Anthology 1989-1997 Blu-ray: ...
A penny cheaper too!