Finally picked one up. This is one I've been undecided on, pretty much since release. However today I saw a second hand copy in the window of my local CEX (UK equivalent of Gamestop) for £10.
Surprisingly it was in mint condition. I'm happy to now own the movie but the steelbook itself? Yeah I think it really is only worth about £10.
Pop art steelbooks can, sometimes, be done well but when the theatrical poster art, used on the amaray, is so clearly superior then why oh why go this route?