They didn't hire you because you brought a special deck of cards to the gig, they hired you because of YOU.
People didn't hire you because you dress well, they hired you because of YOU. Surely you wouldn't argue against a performer dressing appropriately for their character and the surroundings, though.
People didn't hire you because your routines are your own original creations, they hired you because of YOU. Surely aspirations to creativity aren't to be dissuaded, though.
People didn't hire you because you use an elegant Colibri gold lighter to light your flash paper with rather than using a cheap plastic Bic thing, they hired you for YOU. Surely attention to details of props and costuming is professional, though, isn't it?
People didn't hire you because they like your hair, they hired you for YOU. Isn't turning up to a paid engagement with unkempt and unwashed hair discourteous, though?
My point is that it doesn't matter whether any particular detail of your theatrical choices is a dealbreaker. I think that YOU, the performer, are there to put on the best possible show, paying close attention to every detail. If that can be facilitated by a make-up choice, a costuming choice, or the choice of an appropriately designed deck of cards over a standard one, then it should be done. This attitude of "the spectators don't care, so I don't need to" seems to have a flaw in it. Most viewers of, say, Downton Abbey don't know the details of Edwardian fashions. Does that mean that the makers of the show should take the attitude of "they aren't watching for the costumes, they're watching for the story" and disregard those details?