I'd avoid that ticket (along with all EBAY sold tickets) like the plague.
Looking closely at the ticket it states, "VALID FROM 12/30/99 EXPIRING 12/01/12". So you only have November to use it. And with the parks typically closing early in November, you'll probably only have a couple hours to use it.
I suspect that they obtained a multiple of these tickets and are now trying to sell them before they expire Dec. 1, but there's not guarantee that these tickets haven't already been used.