So you come up to your crafting machine, scroll down to your favorite item to make, and it lists 0 (blank) items can be made. You view the ingredients and you realize you've run out of thread, cooking salts, etc. You got to stop what your doing and go buy the vendor ingredients which sometimes is a ways away (aka cooking) and come back.
Why not put the vendor bought ingredient buying directly into the crafting machine screen? Or simply subtract the cost from your bank account for every item made with the ingredient. Result is less time running around buying ingredients and more time crafting?