For the most part these rares either hold their value or increase in value, like that of a stock, since no more rares will ever enter the economy and the number of discontinued rare items may in fact decrease, for example if a player destroys the item. It was suggested in a live video by Mod Mark that if a player with a large number of rares was banned, consideration would be given to reintroducing them into the game, possibly via the Grand Exchange.