'Original letter from Rob?'

I found this letter on eBay and am really wondering if Rob maybe (for some reason) remembers writing it?! I really don't have that kind of money to spend on a piece of paper addressed to someone else (I think I would spend it if it were addressed to me ;) ) BIG QUESTION: If you have a personal letter like this, WHY the *&$@# would you sell it?!?!?!? For whatever amount!!!