In the case of a repaired piece lost in the mail--
First, chances are it will eventually turn up. Let's hope your
"account" is honest enough, and on top of things enough, to let you
know. (A book I ordered in early December just turned up in my
mail-- long after the order was credited back to me.)
More to the point-- when you send things uninsured, you are
"self-insuring". In a professional practices seminar, Barbara
Heinrich described that she does this with all parcels up to a
certain value. The difference is, she puts the savings into a
special accound. Any losses also come out of this account. I guess,
other than making accounting a lot easier, what this does is ease
the sting of losses by making it clear that you are saving money
overall by not paying for insurance.
As for charging for repairs, if it is because of a defect (or
possible defect), then. of course you should not charge. If it is
demonstrably from abuse, well, that's a tougher call. I think that
the largest single difference for the customer in dealing with one
of us instead of a mass-producer or importer is personal service.
From all the postings here, I've concluded that we need to build
enough "air" into our prices to be able to give excellent service,
including no-questions-asked repairs. It seems likely to me that
this helps a great deal in creating the aura of "class" around us,
and builds trust. The short-term loss is, one assumes, more than
made up overall. We hope.