How Much Does Damage Affect Value?

did the UPS store pack it or just ship it? if the former, as far as I am aware, they guarantee their packing to be to UPS standards.

I believe the UPS Store owner told me the seller had asked his opinion of the package when it was brought in and he felt it was acceptable. For normal handling and drops from lets say 2' or so, the original manufacturer's packaging would be fine, but apparently UPS has to drop their packages from 4' and above as part of their service. I read somewhere that if the packaging cannot survive 4' drop, then UPS would deem it unacceptable, in which case I'd have to agree, it would not survive that kind of drop. Very risky to ship this particular item because of the transformer layout I described.

Since most products come up often on Audiogon and many in near mint condition, trying to sell one with damage takes a lot off the original used price, figure at least 30 % but probably more like half.
I recently had this problem with fedex and was amazed when I filed a claim and they refunded what I asked for quickly and with no questions asked. I passed on the savings to the buyer and we made the situation work... explore your options.