I marked up costumes for my 29 years of owning my studio and I am SO glad I did. Now that I am retired I have a very nice nest egg in the ol' savings account!
This question about marking up costumes comes up alot and I have said it before and I will continue to say....think of your future,put that profit in a savings account for your future. I don't want to disclose how much I marked up costumes on a open board as I know for a fact I have former students on this site, but if you PM me I will be happy to share with you.
Tutuforu