I bought that box three weeks ago, but there's nothing in it you'll miss. It contains Base and Cornucopia and all the promo cards (except Governor). When I bought it, the price was only 5€ more than Cornucopia, and since I missed that expansion and the promo cards, it seemed like a good offer to me. Having a new Base Set (and with that, "fresh" copper and stuff like that) isn't that bad, either.
However, Hans im Glück (the publisher in Germany) messed something up again: Stash doesn't have the red back. They will send you the original Stash for free if you contact them, though - so it's not that bad.