Here's my $6 off code
[MOD NOTE: Code Removed.]
Not as cheap as via Steam but there are downsides to using that unless you are already using Steam for other purposes. See YNAB's own discussion format re that topic.
Another tip is to take out a 34-day trial and sign up for as many of the free webinars as you can. They give away at least one subscription* at every session - sometimes 3, and at the one I watched on New Year's Day everyone was given one, including me! There was no advance notice that would happen. And yet I still got the $6 off to you /$6 to me code. Clever marketing: certainly enough to make me feel like a supporter already.
* once-off activation code /licence code (thanks for the correction, Will)