You can now get the Marvel box set for £28:
https://www.sainsburysentertainment.co.uk/en/Films-TV/Blu-ray/Robert-Downey-Jr/Marvel-6-Movie-Collection-Avengers-Assemble-The-Incredible-Hulk-Iron-Man-Iron-Man-2-Thor-And-Captain-America/product.html?product=E11096149