There seems to be quiet a difference between the price of quality 2 and quality 3 safety components. Sometimes it seems possible, to save money by using a quality 2 safety component instead of a quality 3 safety component, and use higher quality materials of materials with a smaller difference in price between quality 2 and 3. This might result in a lower total price to craft.

I am not quite sure I understand.

The material suggestion feature already tries to give you the combination with the lowest crafting cost that still reaches the desired threshold

I believe their suggestion is to also be able to suggest changing optional reagents. If a tier 2 optional reagent adds 20 difficulty and costs 500g, a tier 3 adds 15 difficulty and costs 15,000g, and the extra 5 skill can be made up by using higher quality materials costing another 3,000g, it is more cost effective to use the tier 2 reagent and higher material qualities to make up the difference.

I put this on the todo, but will take a while to implement due to its complexity