I could imagine that the Apple iWatch Edition will generate a lot of repeat buyers. A good trade-in program would recycle your precious metal and refund that to you. You could keep the straps. The price for your repeat purchase could be then a fraction of your initial buy. You could constantly renew your statement with the Edition line and stay current. Ephemeral disrupting Eternal.
Even if it’s not upgradeable (being able to replace S1 with an S2), there ought to be a decent trade-in value for the gold alone.