At some stage smartphones will become as cheap and ubiquitous as Nokia feature phones were before the iphone took hold. Sure they will have some secondhand/stolen goods value - $10 - but buyers might be hard to find as, by then, it might cost $30 to buy a new one. When this point happens (and it will), it will be hard to sell $$$ mega-bucks phones as new or into the second hand/stolen market.
People used to burgle houses for VCR's once, and for DVD players. Nowadays a DVD player is a giveaway item, nobody gets them stolen anymore.