The funny thing about that ebay listing is that it claims the guitar is NEW. I must believe if it was NEW then Martin would be selling it themselves or have it in their museum, not some yahoo on ebay. For the guitar to be NEW that means this guy bought it, and had people sign it and never played it at all. I just don't believe it.
This past summer, some lady had backstage passes to a performance, got the signature from whoever the famous singer was (I think it was the guy from Korn maybe, I don't really listen to that stuff myself), drove straight to my husband's tattoo shop and paid my husband to tattoo a copy of the signature on her body. I don't think it gets any more strange than that. I'd rather my guitar be sharpied than my body tattooed with a signature.
Art and beauty are in the eyes of the beholder.
What constitutes excellent music is in the ears of the listener.