where to get gluten free flours?

So I went to the local east end co op due top they have bulk flours. But they said there not permitted to label them GF because they are in bins. where is a good place in pittsburgh to get GF flours and grains..and is it bad to buy it like that at the co op?
im looking for someone with experienced gluten free baking do you buy it bulk or what?

Whole Foods or other organic type stores may have some. A fairly new website which I really like is http://www.GlutenFreePromise.com They have all sorts of stuff, including a large selection of flours. Hope it helps.

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