Manufacture in place using a crypt top smelter/forge/portal outpost. Reduces need to ship iron out of swamp by 90% unless you use a lot of iron for building. Requires only one run in (with Haldor's belt) to carry the necessary bronze age mats for initial setup, everything else can be portaled in - no portal'ing of metals required.

Not doing that is like killing Bonemass with a spear.. can be done.. just really painful.