Are you in the UK?

I don't find it at Amazon here in the U.S., but I did a search on eBay and find one auction with the DVD, for region 2. That's not the U.S. region, and perhaps you know what plays in your area. If it doesn't match your region for commercially sold DVD players you can still play it on your computer, and if you get a copy of the free software DVD Shrink, you can make a copy and change the region when you burn that copy. You'll need to hop on it, though. It is item number 200073283435 and it closes in 3 hours 46 minutes. It goes for GBP 3.00 right now.

SRS