You want me to clear a field, stand and wait the few minutes for them to respawn in the hopes that 1 or 2 might be a DB holder? When I fly around I see a DB holder every 15-30 seconds. I've killed so many my inventory fills 3 times while i'm hunting. I have 4 of the biggest cash shop bags you can buy so that takes quite a lot of items that weren't dragon balls to fill that up. xD
If your seriously telling me that I need to kill more than that, then obviously the drop rate is way too low
Ah so area matters then? Why is the drop rate so much higher there?
Edit -> Well I guess i'll try that area next week if I bother to come back on lol. Just saying it out loud kills my chubby for this game. "I have to wait another week before I can even try again." No other game coming to mind for such a thing.