Thanks to Christian Longstaff for pointing out that Expression Web is available to download for just $US99 as an upgrade from FrontPage, Office (any version) or if you're an owner of a bunch of Adobe products.

http://blogs.msdn.com/chlong/archive/2008/02/12/us-99-expression-offer.aspx

Of course, if I had my way we'd be dropping them from the back of airplanes...