I'd take a regular 5x8 notecard box (the type your wife keeps recipes in).
Buy some inserts
cut up an old aluminum arrow into 1" lengths
glue inserts into each 1" *arrow*
then glue the *arrows* into the base of the box
That way they're secured and touching NOTHING.
Anything that touches those blades will dull them, the question is "how much"
You can dip them in hot wax or do some tricky masking tape work to cover the edges if my idea is just way too much trouble (I understand if it is...but hey, you'll have a broadhead box for next time!)