well kaneda when i played i used a combination of MF and skills and resist. i mean if i can kill meph/pindle in 2 less hits while where skill/resist gear and still have about 350-375 mf i was happy because i could do more runs and die less often. and Mf is just luck mainly anyway. i think actually optimum mf amount is somethin around 350. because once you go higher you find more magic items and rare items but your amount of uniques only goes up by something really small like 2% by every extra 100 mf. Not sure if you really will be able to understand that but i hope it makes some sense.