Alternate costumes for characters

I think, someday, we should add alternate costumes for characters.
I'm not talking about alternate palettes, but alternate selectable sprite sheets for the characters. Maybe some could come with their own sounds?

It could be a really good way to add popular characters that are too similar too each other. That way we could have Lucina, Roy and Chrom all sharing Marth's spot in the roster.

Basically, it's like how you can select Wario's classic clothes or his biker clothes in official Smash games.

Thoughts? Any suggestions?

The only problem with that is it takes space and time, when space and time could be used on other things, such as entirely new characters. They wouldn't be as time consuming, because they could just be traced over, so no new animations would have to be made, but that time could instead be put into new characters, or resprites of older characters.