Aren't the DSWare version of app games more fully fleshed out? And as I'm sure you know, 500 point is $5, and iOS has $9.99 games already, which could easily appear on the 3DS with upgraded visuals for 1000-1500 points.
Edit: I never said there would $.99 games on any DS.
As for my second point, I can't link from my phone so you'll have to use the magic known as Google and search for "Apple premium games section". It's just a rumor at this point, and the for now, the games are rumored to be $20 and not $30. I assume however, that as the iPhone/Pad/Pods get more powerful, they'll get more fully fledged games, that cost more to develop, and thus have to be sold for more. Since it'll digital distribution only, $30 came to my mind as the ceiling for such games.