First off... Point Blank Shot?
Secondly, I'm guessing something prevents you from destroying stacks of arrows. Either you're really frugal and want to sell them all or you're going so fast through the quest that you don't have time to stop and destroy stacks of excess arrows.
Dogan
Slow is better, trust the Doctor. http://www.youtube.com/watch?v=t4mpbw68_HA