01
Case material, size and cellular set the number
An Apple Watch is priced on its case before anything else. Aluminium sits at the bottom, stainless steel above it, titanium above that, and the gap between aluminium and steel of the same generation is wide enough that guessing costs you money. The Ultra is titanium at 49mm and holds value better than anything else that reaches us.
Size counts too. The 45mm, 46mm and 49mm cases clear faster than the small ones, while 38mm and 40mm sit at the softer end of the market.
Connectivity is the third lever. Settings shows a Mobile Data entry on a cellular watch, and several generations mark it with a coloured ring around the Digital Crown. Cancel the plan with your operator first; it stays tied to your number otherwise.
02
Crystal, back sensors and the swollen-battery check
The front tells you what the case is made of. Aluminium models use Ion-X glass, which picks up scuffs from door frames and gym equipment. Steel and titanium models use sapphire, which shrugs most of that off, so a scuffed aluminium front is normal wear while a deep gouge is a different conversation.
The failure worth finding before you travel is a battery swelling and pushing the screen out of the case. It shows as a lifted edge, or a gap you can catch a fingernail on, and it is common on older generations. We still buy those watches, priced as a screen and battery job, so say it up front.
Turn it over as well. The back crystal holds the heart-rate sensors, and cracks there hurt more than marks on the case sides.
03
Bands, the charging puck and the box
The watch is priced on the case, not the strap, so a worn sport band or no band at all will not sink your offer. Bring whatever you have.
Original Apple bands do add something, and the metal ones add the most. A Link Bracelet, a Milanese Loop, or the Ultra's Alpine, Trail and Ocean bands carry real value on their own and are worth digging out of the drawer. Third-party straps cost very little new and move our figure in neither direction.
Bring the magnetic charging puck if you have it, since a watch without one is something the next owner has to buy. The box is a small plus, no more.
04
Unpair it properly, or the watch stays locked
This is the step that catches people out. Unpair the watch from the Watch app on the paired iPhone: My Watch, tap the watch at the top, then All Watches, the info button, and Unpair. Done that way, the watch is backed up and Activation Lock is cleared in one move.
Erasing the watch from the watch itself does not clear Activation Lock. It reaches our counter wiped and still tied to an Apple Account, which we cannot pay for. If the paired iPhone has been sold or lost, remove the watch from your Apple Account online first.
While you are there, open Settings, Battery, Battery Health and send the maximum capacity figure. watchOS states it plainly, which tightens the quote.