ANot disco dust but the edible shimmer dust. Cupcakes and cakes.
I use that often and never charge. You can get a lot of use for one small jar of it and its not that expensive anyways so I don't think it would be worth charging extra and as long as your prices aren't super cheap it should cover the small expense of the pearl dust.
Nothing. And I use it a lot. A little goes a LONG way.
it is included if the design calls for it.