$650 is the price when the seller is in no hurry whatsoever and is willing to wait years to maybe snag a chump... or ah... a serious collector. I'd guess that if there are multiple people thinking they can sell it for somewhere in the $160s you can probably get that eventually, though it might take reposting to ebay a few times.
The content seems to all be available for free online which has to drag the price down a bit. Your target audience is people who want digital dragon magazine but would prefer not to get it online (or did not think to make a cursory glace as to whether they could) and who still have a CD-Rom drive on their computer or else people who prize the CD itself as a collectable. So its probably a fairly small community of prospective customers, which is why I would say that even if $165 or whatever is the going price, it would likely take a while for it to go at that price.