digitalv - 1:54 pm on Mar 1, 2011 (gmt 0)
The cost of shipping is insignificant next to the loss of revenue from having your name on complaint sites.
Tell him you'll reimburse him for the shipping after you've received the item and confirmed that it's in good condition. When you get it back, if everything checks out refund his money and send him a prepaid gift card to cover the shipping, rounded to the nearest $5.00.
Little things like that go a long way.
P.S. - As a general rule, it's better to do everything possible to avoid a charge-back even when you know you're right. Bad news travels faster than good.