i think that the hard reagents to find should be easier to find like gold pearl and diamond and especially scrap iron it took me forever to finish the marleybone crafting quests because of the scrap iron and my friend said that the celestia crafting quest you have to find 6 gold pearls which took him forever to find and i am not looking forward to that one.
Reagents are just fine the way they are, part of leveling in craftng and reagent harvesting is learning where to look, tranmuting them yourself, harvest from gardening, or boss farming. There are lots of ways to get these reagents, an hour or two going in a circuit in pearl rich areas should give you at least 2-3 golden pearls and then enough regular pearl to transmute the others. Seriously reagents are way to easy to obtain any easier and all the challenge would be lost, I say that as a Grandmaster Artisan who has made both Watchtower Hall and Celestial Observatory.