I'm currently @ 51% Experience and 6140 sp (farming SP, slow EXP

) - LVL 31.
I was doing the premium quest until the 3 hours expired, the items were no longer dropped. I joined a 8/8 auto-share / item distribution party and started killing monsters. However, not one monsters dropped one for 1.5 hours or so. Why?
Also, wouldn't it be smart to kill lvl one monster while doing this quest? Or would they not get dropped at all (slowest drop rate?). I was killing lvl 33 monsters during my attempt.
Help is appreciated. Thanks

.