Realizing that there's no perfect solution, what 2 or 3 programs are
generally considered state-of-the-art (or at least best-of-breed) for
client side, (probably Bayesian based, but not necessarily necessary)
spam filtering for Outlook 2000?

Are they priced on a one-time fee or subscription basis?

Hello cdh99,

I can honestly say the best spam filtering solution is a program
called POPFile, and its free!  Their website
(http://popfile.sourceforge.net/old_index.html) has everything you
need to get it up and running (it will take about 10 minutes or so to
set it up, but its well worth it).

Another solution would be Spamnet
(http://www.cloudmark.com/products/spamnet/).  It is alot easier to
set up, but isn't as effective.  Also, they charge a monthly fee of
$3.99.

Please let me know if you would like more information about either of
these 2 services.

We have had decent luck with Spam Bully http://www.spambully.com which
is Bayesian based. It does work on Outlook as well as Outlook Express.