LAST EDITED ON 18-06-01 AT 08:41 PM (GMT)
There's of course the NYCB website. I suspect they sell all the NYCB videos available, so if you can't find it here, you probably won't find it anywhere else. Incidentally, I think Darcey features on one of them.
sells quite a few videos. They also tend to be £3-4 cheaper, because delivery is free (I think), and the range is quite good.
http://www.shopsmart.co.uk. This website will compare prices of everything from reputable online shops.
Seems to be a popular one.
And of course
The american version http://www.amazon.com has a wider variety of US videos in stock.
Hope this helps. As you may have guessed, I do far too much ballet video shopping online.