There is a much earlier time you can get this achievement!
Once you earn the Enchanting Ability after rescuing the citizens of Sapran, you can go back into town and purchase all of these materials required.
I had the "A" and "B" vouchers on hand, so I'm not sure if they were required or not. Anyway, get them just to be safe. They're free!
Now the method that Crimson did is still a useful crafting method to do it. But I'm going to add a couple numbers for the frugal.
Start with "Air Attack". Craft this about 15 times. You'll hit IC2.
(1x Cork Wood yields 1x Air Attack)
Craft "DEF +5%" about 15 times. You'll hit IC3.
(1x Bronze Metal yields 1 DEF +5%)
Now purchase about 15 more Bronze Metal. Craft "Autuguard Rate +10%". You'll need about 15 to reach IC4.
These numbers are rough estimates, on the high side. I had a few failures in my crafts. Actual ammounts may vary.