The extra gold pickup radius affix can appear on all types of armor pieces, that means +7 yards/piece.
It is easily possible to get it up to like 50 yard radius, which is more than half of the screen.
Ok, 50 yards might be a bit overkill, but 30 yards should definitely be enough.
So this means 1% mana, life and -1 sec cooldown on skills after each dead mobs around us.
I think with the radius boosted to this extent, Grave Injustice can be even more useful than the so praised Soul Harvest.
Cd reduction makes Hex a really awesome skill, (2 shamans up) Zombie Wall could also benefit greatly from this (the 3 Creepers), not to mention Zombie Dogs and the sacrifice builds. Especially since it will be possible to reduce cd of the dogs by 9 sec with the Zombie Dog cd reduction affix.