This brings me too a discussion I had with a friend... A little off topic, but something to consider???

For what it's worth, I shoot Thunderheads that have replaceable blades and so does my friend.
Here's MY theory and I'll start form the beginning...

1) Once I've deemed my practice arrow(s), a straight, consistent shooter, it graduates to the next level.
I then take my selected (4-6) arrows and place an old broad head with dull blades on it.
2) Then once again I'll shoot at a target and then deem it good for a "hunting", from there
it graduates again! (yeah - good broad head!!!)
3) I then put a new broad head on it and shoot it only once into my target, to re-qualify for the end result,
an accurate "hunting arrow".
From this point on, these arrows are quarantined for hunting only and never re-used, except to kill something.
Note: During my bow season I use a few of my dull practice (broad head) arrows for practice,
as not to ruin my virgin (ha-ha, I said "virgin") arrows.

Theory ~ The blades are cheap enough and most likely sharper than anything you or I could do, in my opinion??!!

Reason for theory...
I was at a seminar about 10 years back and they did a test to prove how important a sharp broad head is...
The instructor shot a tight, 4" diameter wad of elastics (simulating the heart) with a factory sharpened broad head,
and the second 4" ball with a "amateur/duller" sharpened broad head.
The results of the actual number of elastics that where cut/nicked, when unraveled,
from both of the broad heads amazed me!
The factory broad head cut 78 elastics, while the duller broad head cut 46 elastics - Wow..!!
This exercise was to show that the elastics are supposed to be arteries
and veins and as we all know cutting more veins should equate to a cleaner faster kill.

So the moral to my (boring) story is, don't be such a tight wad!
You can salvage/retire the old broad heads for practice.

Lastly, I only used 1 arrow last year, so how expensive can that be, to be able to sleep peacefully at night?!!