You probably shouldn't rely on the Online Rarity Guide's numbers as they haven't been updated in far too long. They are really only good for N64 and earlier, and even then only on the rarity side of things as game prices have changed quite a bit in the past few years. Basically, if anything listed on there has a price of "0" or a rarity of "0" then it typically has incomplete information. Thus I'm fairly certain that Radiata Stories's rarity rank of "1" is incorrect.