I think this is quite different from the Witch Hut. If I understand the suggestion correcly, this would allow players to generate EXISTING voodoo cards. I assume specific cards. If so, that would affect the voodoo economy dramatically. As it is today, a more or less equal number of cards are generated within each category of common, uncommon and rare. If people start making specifically the cards they need, that would have huge consequences. Not necessarly negative ones, but it needs to be thought through thoroughly.
As a side note, there is already a way to get voodoo cards from "resources". It's called Booster Packs!
@Captain Jack: Will there be no Witch Hut? Or will it be, but not as a hideout building? What are your plans? Do tell!