Value to whom, exactly?

I have always been a follower of the belief that something is only worth as much as someone is willing to pay for it. So while watching a video about the San Diego Comic Con, I was puzzled by an old Flash comic, graded (and therefore sealed) of course, going for $65,000. Why in the world would anyone pay that much for a comic they can't even read? Just to sell it to someone else?

I will never buy a graded comic, and will never send my out for the treatment. I just don't get it - like people who won't take Transformers out of the box.