Accepted Make Diamond Arrows Boughtable At Custom Amount(s) or Rechargeable

Hello,
I'd like to ask making NPC Mo in CWK sell Diamond Arrows being bought at a custom amount.
As for current state, Diamond Arrows (for Bows) are being sold by Mo at an amount of 2000 arrows a time.
Each set/stack comprises of 5000 arrows.
Bowmasters use these arrows (if one chooses to enjoy an extra w. attack instead of using Soul Arrow skill) at such fast rate making one to seek for much sets for each boss run/grind.
Instead of making countless trades/chat boxes with NPC Mo, much more efficient approach will be to enable one to buy these arrows by a custom amount (blank box one would have to fill).
I'd stress that making these arrow sets rechargeable will be a proper change as well.

Thanks for your consideration.