That pesky salt/titanium.
I can live with 30/60 granite and 40/100 exo logs or 100 gold ore from a 24 hrs search (fast scouts). Unfortunately with this economy a scout bringing 10 salt/titanium ore (24 hrs fast 48 hrs normal) is just way too little.
Canon forge consumes tons of gunpowder which is extremely expensive (resource wise) to make (even 3x buffed). Unfortunately, while re-balancing loot, salt amount was not changed much. One in 4-5 BK's I get 250 salt which is really a pinch if I want to run gunpowder hut. It would't be a problem if there was salt available on TO. Unfortunately, since every one is forced now to make weapons - everyone needs it and the adventure loot is a drop in a bucket. Treasure search will not help here either.
Similar situation goes for titanium. There is a huge shortage of both resources and it is adding to the long production cycles of epic weapons (which is another obstacle).
This is becoming a problem that is not going to go away, because no matter how much players stock piled of those 2 resources, those stocks are dwindling now and not growing.