Yeah, there won't be anything rare anymore. Unless selling an account with a Golden Scythe, or some other untradable item. Won't get too much value as it is untradable of course. Those items became rare as Runescape still was just a baby with not a huge playbase and most people got rid of those items rather than kept them. More players joined and database grew with the demand going higher for those items. Now, everyone has an idea on virtual rares and their value and their are too many players. It just isn't entirely possible anymore. Only if they supplied something very limited like one drop party of 10 of this item and it would have to be something everyone would want to have and tradable.
Rare items and Runescape has lost that magical, respectable touch for good, at least to me.