Blizzard didn’t seem to take into account the difference between Engineering and other professions when they decided not to provide materials for patron orders. Currently, there are 5 patron orders available to me, and the price of materials I have to provide ranges from 15k to 30k per craft. Even at the end of the expansion, crafting a wormhole with most of your materials is expensive.
If they decided not to provide a somewhat similar amount of materials in all professions, they really did not think of the difference in the price of those materials.