What is the cost of testing compared to new ones and what is the failure rate? I assume you pay the same to test failing gloves as good ones.
My experience is that the cost of testing is quite low vs new gloves.
The thing is, if you keep your leather outers in top condition, by rights, the actual inners should last a lot longer.
Using things like leather care products (that are allowed by the manufacturers) on your outers, go a long way towards keeping the leather supple and this then means it doesn't damage the rubber inners.
We used to send a tonne of gloves away all at once, so it was done at a cheaper price per glove.
Having said that though, Greg, if you are field-testing your gloves, before they are worn, this cuts down on the number of "bad" gloves that are sent in for testing.
If you have a glove that fails a "roll-up" test here it is cut up and discarded.
Even so, keeping a close eye on your outers, can mean the difference between maintaining a decent pair of gloves and wrecking a perfectly good set of gloves when you get a wire strand through your inners, through a hole in your outers that you never noticed was there.