Which area you farm is decided by the area's monster level, not by the item —
the rule is the same for everything, so it lives on the
mechanics page.
NAMED TARGETS
Named monsters that can be farmed deliberately. The list spans all three difficulties;
each monster appears once, at its most rewarding one.
The figure is an estimated average kill count.
Diablo
normal · Lv 110~1 every 20,076 kills
Izual
hell · Lv 86~1 every 22,028 kills
Bremm Sparkfist
hell · Lv 88~1 every 33,654 kills
Geleb Flamefinger
hell · Lv 88~1 every 33,654 kills
BASE ITEM DROPS
expected per kill
This counts how often the plain Ring drops. A dropped base still passes
a quality roll before becoming this item.