level 18 conj, i get around 8000-9000 an hour.
There is a leve that constantly generate evefly, get that mission, turn on guardian invoke.
Then start grinding the imps until you have 1 pair left, leave the area and level near by killing stuff (guardian invoke doesn't work on anything outside of leve monster) and return to kill the evefly whenever they respawn (also use your detect all)
I got around 2-3k from guardian leve alone. within that 30 min, if you get 2 of these level, you can get 5k roughly from both, if you do grind while waiting for the evefly respawn, you can get up to 5k roughly.
Remember, turn shockspike off. Never use it.