MM and Sonic are uncommon. You should be able to find them with relative ease along with Shiek, Toon Link and Bowser.
I'd say no. Easily grabbed megaman and saw plenty sonics when shopping recently.
I see. They didn't seem rare but I wasn't sure. I thought Shiek was gonna be rare, but I guess she ended up common?
Everyone except Bowser, Toon Link, Shiek, Sonic and Mega Man is rare.
Rarest of wave 3 is probably Rosalina, Meta Knight or Shulk.
Rosalina actually ended up rare? Damn, I messed up not buying multiple when I had the chance. But oh well, scalping's too much of a hassle and I mainly care about having the figures to use in games and shit anyways.