I use a little 'trick': I have Tier 1 and Tier 2 of material (which is cheap) and try those. If they will not give me the full potential, then I do not even look for Tier 3 or 4. If they do, then I buy the next Tier and try that, and so on. Worst case scenario is that I get the max benefit of Tier 3, which happens to also be the cap limit, so I am 'stuck' with only 1 Tier 4 which I can try to use next time.