I am looking for a used Tesla Model S and they are going for about $55K right now in Southern California. The value is holding up extremely well; However, Tesla just announced a new MS 60 for about the same price (may be less with tax credit). With the new 2015, you get the full factory warranty, more reliable car, can upgrade the battery at later time, or get it with Autopilot. I think this new offer from Tesla will change (lower) the used car price for a pre-2015.