The trouble is the ratio to level. 57-58 is a 3 mill level.
100 leve's standard with 56 give around 2.1 mill experience, should someone be insane enough to even consider doing 100 leve's in HW where it takes half an hour to walk from one end of the bathroom to the other.
10 bulk Leve's at 56 only give 800K. A little over a third of a single level for all your leve points. Using Bulk leves it would take you 3 weeks to get one level.

Battle Leve's are complete and total, unmitigated garbage. Always have been, I suspect, always will be.