People about Cosplay...
The only place it should really matter is in competition. Don’t enter a workmanship based contest with something that you bought or commissioned, and don’t take credit for the work of others.
That said, some contests have a category for commissioned or purchased costumes, you would be fine if you entered there.
Absolutely! Just not in the way your potentially-leading question could be interpreted to imply.
Wikipedia says that “cosplay” broadly applies to any costumed role-playing in venues apart from the stage. Therefore, it’s only the growing and disturbing layman’s trend of equating “cosplay” with “manga/Japanese” which makes it appear there’s a problem. My generation was cosplaying before the term was coined (c.1984), and thus we “costumed” at conventions as characters from Star Trek, Star Wars, Ghostbusters, Doctor Who, Marvel and DC comics, etc., none of which are anime or in any other way Japanese in culture. Even if some were, most other characters equally originated from different countries and cultures, so on the surface the answer would appear to be “no”.
Now, is cosplay appropriation of any kind? It’s actually nothing but! By definition, cosplay is of a previously-established character from a previously-established distributed media venue (TV, film, books, etc.). You’re always cosplaying a character which someone else invented, or at least basing in on one (crossplayers, etc.). You’re not asking the creator of said character to do so, so yes, you’re appropriating it. But it’s an appropriation of trademark or license issues, not of culture… all cultures are potentially fair game for it.
Finally, cosplay itself has matured and spread enough that Wikipedia already classifies it as a “subculture”, which I suspect is a conservative definition if you’ve ever been to a comic-con.
So: cosplay is, in the end, a “culture” based on “appropriation”. If we concede that this encompasses any culture and appropriation, then your answer is a resounding and unabashed “yes”.
First of all, cosplay isn’t just about playing dress-up. Cosplay is a whole lot more than that. Good cosplayers will act like the character while in costume or move like the character. Serious cosplayers won’t break character when they’re in costume. It’s a little bit of acting too. But it’s a culture that’s meant to be fun.
You see, cosplay is a couple things. First, it’s a service to the fandom because other people get to essentially see their favorite characters in the flesh for a couple hours. And this is especially true if you really fit the character. But it’s a lot more than that. It’s a chance to be someone else for a little while. When you put on cosplay, you get to leave your life behind for a little while. And for the people who make their own costumes, it’s a chance to not only show off their knowledge of the character, but it allows them to show off their costume skills and say “I made that.”
So, there are a lot of different appeals to doing cosplay. Besides, with all the photos that people take of you in a day, it kind of makes you feel like a celebrity. :)