Interestingly, Michael tweeted this about the price about 14 hrs ago:

Get All in One SEO Pack - Pro Version + support for $3/mo while it's cheap before the price goes up. http://retwt.me/1L1sP— Michael Torbert (@michaeltorbert) February 16, 2010
Get All in One SEO Pack - Pro Version + support for $3/mo while it's cheap before the price goes up. http://retwt.me/1L1sP

I couldn't find out what the price was going up to, or when, on the wpplugins site

Also, I recall Michael talking about the available pricing options at wpplugins before, I think at weblogtoolscollection.

http://weblogtoolscollection.com/archives/2009/12/23/trend-for-2010-paying-for-plugins/#comment-1323110

As plugin developers, our hands are tied with the pricing structure. The way it’s set up, we set a price for exactly two things: 1) download price 2) download + subscription (for support and updates) price. I absolutely agree with you, I’m not a big fan of the current structure either, but for now that’s the way they have it.

http://weblogtoolscollection.com/archives/2009/12/23/trend-for-2010-paying-for-plugins/#comment-1323099

Interesting to see this come up again, and to see the radically different pricing at wpplugins