They actually went down to $12 at one point. Even though I generally find 2.0 sufficient, the extra pizazz and the Emsi make it a good deal.
However, then it went back up to $20 (50% off). I sent them a note asking about trying to restore the lower price, or when it may return.
Presumably it is a one-PC license, although that might still allow multi-installs when you work on one at a time.
Why they sometimes show both the one and three options, and other times, not, leads to a bit of a puzzle.
I'm not a big fan of this "rush, get to the store, make a purchase on the specific couple of days thing".
It is like you are being played as a cog in the mercantile wheel.