The only time for me that money enters into it for lost/broken items is when you can't get a replacement. For example, if you have a book that you bought and I borrowed it and broke it somehow, I have to replace that book. If, for whatever reason, that's not feasible, we have to work together to find a solution. If, like a PP said, the book originally cost you $10 and it turned into the next $10,000 deal to have an exact copy, that's probably not going to happen. On the other hand, I might be able to find a copy of a later printing for a reasonable price. You won't be getting the exact item back (first edition, limited print run, other limiting factor) but you will still have a copy of the book.
Movies are a different thing, though. If I lent out a limited edition DVD, I would expect a limited edition DVD back. The only way that a different edition would be acceptable is if it had all the features of the DVD I had lent. One of sis's friends was talking to her, had lent out the 2-disc extended edition of one of the Lord of the Rings movies and was returned a basic version. Apparently somehow the discs had broken, and the person borrowing them thought that this was acceptable to buy and return, but in that case the lender is in a worse position than he was before.
It's not about replacing the exact item 100%, nor is it about the replacement cost. It's about making the lender whole, and putting them in the position they were in before they lent something out.