Again, what is the point in getting more crystals than needed? We are not hurting on inventory spaces at all. Instead of buying 20 stacks of ingredients to make whatever, why not just buy 1 stack of ingredients at a time and sell what you have on AH, or, in case buying one stack of ingredients at a time isn't feasible, have a mule that holds the ingredients and make one stack at a time.
There is no need to have a crystal mule, or to hold extensive amounts of crystals.