Currently the only way to obtain Unreplicatable materials is to purchase them with Dilithium and thus placing an enormous price bar on mid- and late-game crafting that makes most people wave it off.

It occurs to me that the DOFF system could be used to give people the ability obtain Unreplicatable materials without using their hard earned dilithium, or at least, not so much of it. A pair of "Trade" missions that reward 5 common or 5 uncommon - depending on which mission - that appear randomly in sector space (any sector space) and then a single mission that rewards 10 uncommon and 20 common that appears randomly in exploration clusters.