I am 99.9% sure that she makes a majority of her costuming from scratch.

I was fortunate enough to take a workshop from her today and at the end we talked costumes.....she makes most of her costumes from scratch. Even if she buys a belt or skirt, etc., she'll embellish it with found objects. Anything from chandelier crystals to bones from dead animals to vintage buttons, etc. She gets alot of inspiration and 'stuffs' from flea markets and antique stores. And she never uses a pattern. She gets things she likes and then sees how she can use them later for a costume piece. She might take a banjara skirt and add ruffles to it for example.

She doesn't do the 'one-stop shopping' thing you're looking for but I hope this helps.