The Mii costumes are expensive indeed, the stages are even worse, though the characters are fine, afterall, Sakurai is a perfectionist, so a lot of time probably went on making them, so they have to make all that back and more, plus we do have to remember that Namco must be receiving part of the revenue, since whatever is left of Sora Ltd co-developed the game with Namco, so the high prices most surely come so that everyone gets a good piece of the revenue, though that still doesn't excuses the high prices for the stages and mii costumes. Though the worse out of all of this, is this:
http://nintendoeverything.com/smash-controller-app-out-now-use-3ds-as-a-controller-on-wii-u-without-the-game/
Instead of it being free, they are charching 99 cents to be able to use the 3DS as a controller on SSBU, if you don't have the 3DS version.
COMG guide to points: 1 point = Raging. 2 points = Beasting. 3 points = Tearing it up. 4 points = Berzerk. 7 points = Rampage. 12 points = Burst. 15 points = god mode. 20+ points = DIVIDING BY ZERO!!! 40+ points = Youkai (originally Pokemon).
-1 = Negabeasting. -5= NegaRampage. -10 = NegaBurst
