I don't think charging a costume fee is appropriate.  Something just doesn't feel right about it.  There are ways to get around it.  One I don't think anyone's mentioned yet:

If the clothing is specific, try to work something out with a local business.  For various shows, we've been loaned tuxes, various ethnic clothing, etc. for huge discounts in exchange for giving them advertising- a sheet in the program, sometimes (with more exotic clothing), a posterboard of the cast in the costumes in the theater lobby.

I am sorry Bev, but It's not the same thing as spending money on another hobby like scrapbooking or minature golf where your responsibility is to no one but yourself. The theater, as a business, is relying on the actors to perform a function in order for them to exist. If someone misses a scrapbooking class or a round of minature golf there is no loss to anyone but them. If an actor doesn't show-up to a performance it could be catastrophic for the rest of the cast, the patrons, and the theatre. I would never ask those wonderful volunteers, who give so much in order for my theater to exist, to pay for anything. I would be mortified if the theater made a profit because the actors had paid for their own costumes. I have pounded the pavement and spent hours on the phone finding underwriters and donations. We have cultivated a costume loan system with most of the the other theaters in the area including the professional theater and the university. (By the way, the university borrowed costumes from me yesterday.) Just like any business, if you can't afford to do it, you shouldn't be doing it. You need to rethink your play selections and do things within your budget, just like any good business.

Perhaps I'm a little off topic here, but why do CT's tend to budget $ for areas like sets, musicians, etc., but rarely for costumes?  Sure, flats can be painted and reused, but costumes can also be redesigned for multiple shows. 

I've always had mixed emotions about charging fees to people participating.  The argument always goes that people pay fees for every other activity, and they should pay for theater participation as well.  I wish we could get to the point, financially, where we could feel we didn't have to, but the reality is, it's just one more revenue source (ticket sales, concessions, donations, and grants being the others).  And, if nothing else, it reduces drop-outs from the cast once people have a little skin in the game.

Funny y'all should be talking about this. I just sent the following note to my theater's board.

Folks,

I have distributed this to all the (redacted) board members in my
address book. Please forward to any board members who are not
included.

It's come to my attention that a new practice is in place at (redacted) that disturbs me greatly.

It is shocking and completely beyond the pale to omit player bios in
the program, ESPECIALLY due to the "high cost of the program" as I
have been told is the reason. Surely this small bit of recognition is
due the players, who have after all sold advertising into that very
program.

Additionally, I have bit my tongue as I have paid each $15 "insurance
fee" for the privilege of appearing in shows at (redacted). At first I
paid gladly due to my ignorance of how things are normally done in
Community Theater. However, my experience with other groups has taught me that this practice is unheard of and it should be stopped. The
Board needs to swallow this as a cost of doing business.

I hope you know that I have enjoyed my relationship with (redacted) greatly and have done some of my proudest work there. However, I will
not be able to continue this relationship beyond "It's A Wonderful
Life" unless these two practices end. I realize that it is probably
too late to insert player bios into our current programs, and would
certainly not anticipate refunds for "It's A Wonderful Life"
fees...although I'm sure that would be much appreciated by all.

Please consider this before making a snap response. I believe we have
much to offer one another.

Sincerely, (My Name)