I think that multicraft restriction will benefit market speculants. I myself prefer to sell final products, such products often needs crafted components from other classes. If i will become unable to prduce such components, i will need to buy it on the market - so, the role of such components will grow. Most of components are stackable and this makes them more useful for market speculations - this requires 99 times less storage space. So - it will come to the game (.