Just wanted to give a "shout out" to Halbrick Studios. This Australian developer has at least four minis in the pipeline. Their games seem perfect for the minis program and based on the fact that their 1st mini, Echoes, will be releasing next week for $2.99, I'd say that they definitely have the pricing down to the impulse buy level.
Here's a news piece where they discuss the minis program in general, and Halfbrick in particular:
http://www.theage.com.au/digital-life/games/minis-give-megabytesize-fix-20091104-hwg5.html