I just got X-men slimline DVD box set with all 3 films in for £8.
Hope this is of some use to you allm I believe it's instore only and as I've never seen them thought I'd give it a go. These are only the 1 disc versions but they do have some special features on them.
Cheapest elsewhere is £12.97 so I think that's a pretty good deal!
- Thom Morris