Exactly why I would never by a sealed copy, Fred. 

In fact, it's a great argument why CGC should sell for less than an unsealed copy.  You're taking a risk of intentional or unintentional overgrading!

I disagree, but then I don't see it as being much different than any insurance appriasal if you are buying something of value. They gaurantee a certain condition at the point it is sealed.  Once opened, any number of things could happen that could alter the condition. Stan could sneeze while signing.  Coffee could spill. Etc. Charging to slab based on the value also makes sense because if something happens to the item while it is in their care, they are pretty much screwed. So it essential becomes an insurance premium, for lack of a better comparison.

Now, there is nothing that says the book needs to be reslabbed after signing. But, at some point in the future, someone could certainly have every right to question the authenticity of it being a "5.0" book.

Fred,

 Hi, the reason they can't guaranty that it'll grade the same condition is because once it's cracked out of the slab it's being handled. What if Stan caused a defect when it was being signed? I know it sounds crazy, but it's been known to happen. It would be shadier on their part IMHO it they COULD guaranty the same grade after getting signed.

Casey

I think that I could live with that damage if I were able to say "hi" again and see him sign it.