Not really. Sakurai has repeatedly gone on record saying that each character in Smash takes an incredible amount of time and work to create, which is why we won't be getting a flood of DLC content for this game. And we're talking about a man who quite literally worked himself to exhaustion and poorer health making this game.
Mii costumes also aren't expensive at all. They're .75 for one platform. You literally can't get much cheaper than that. You're talking three quarters. You can't buy gum for that anymore.