very likely not. i think one should be cautious with estimation and probability assumptions without enough data (auctions, amazon marketplace etc - preferrably more than one reference) in a thread like this - i mean, how can you go from one 40$ ebay listing to a 300$ estimation. because you've never seen it besides that ebay one? only because something isn't regularly found, doesn't mean it would sell high. rarity has not always something to do with how high it would sell. does it even have high demand? that in conjunction with rarity can pump up prices. Watch Ganbare Goemon albums on Yahoo Auctions, with start price not too high. In very short time it will sky rocket in price. Because demand is coupled with low availability.
to give an example about why 300$ is, in my eyes, not too probable, here:
http://page.auctions.yahoo.co.jp/jp/auction/161661672
sealed cd with the artbook it came with. all for 3800yen. bids: one.