I'm sorry for the slow response to your question. The game is indeed out of print. I don't know that particular eBay seller and cannot verify if what he is selling is a legitimate copy of the game. You may contact our online customer support center for help finding an authorized reseller who may still have the game in-stock. Or you may wish to contact the game's developer to see what his future plans are for the game. Customer support will be happy to give you his email address, or you may send a private message through our forums
http://forum.shrapnelgames.com/member.php?u=6578