Yes, basically. I buy my books very cheaply. But, that's not exactly the point I was making.
Say I ship 1000 items and pay for DC on all of them. That would cost me $550! (I think that's at the new rate.) I could pass on the cost of DC to my customers but that makes my pricing less competitive. I also could take it out of my handling charge, but I need to use that to pay my eBay and Paypal fees.
What I do is save that $550 and use it as my "slush fund" in case a book gets lost. If it happens twice out of those 1000 books, then it costs me about $10 cash out-of-pocket. That $10 is way less than the $550 I would have spent.
I may not be explaining it very well, but I hope that makes sense.