You do need A LOT of iron in this game. In my last game I gathered over 900. But I also have gotten very efficient at it. An average crypt yields around 90, is my guess. So i have to clear about 10 crypts. Go in with portal (on top of crypt), make a run out with 30 or more to the nearest ship base. In about 30 runs or 30 days (one run each day), I have everything I need for the whole game. Transport everything in 2 sailing trips to your main base.

The grind that bothers me most is raising skills. After a certain point getting better gets VERY slow. Running is the only skill I ever get to 100.