My guess is that Tesla will make *lower* than normal offers for trade-ins until they are ready to roll out their CPO program.
Reason being that until they have the CPO program, dealing with used inventory is a hassle. Their systems and procedures aren't set up for that. They're set up to sell new cars.
Once CPO is set, every used car is revenue generator and the hassle factor is gone.
This seems likely. Many of Tesla's offers do seem to be seriously lowball (with the exception of the offers on essentially-brand-new cars).
Tesla claims to be clearing 20% gross margins on new cars. I suppose if Tesla is trying to clear the same 20% margin on used cars, that might account for the lowball offers; but it doesn't seem sustainable, since used car dealers can undercut Tesla easily just by accepting lower (but still highly profitable) margins. If CarMax is routinely offering better trade-in prices than Tesla, that's going to dry up any plans for a CPO market.
Suspect they depreciate options a lot more which means non-P cars probably aren't as bad of a loss.
This is probably also true. Many of the options -- particularly "P" -- wouldn't have nearly as much value in the used market. (The tech package probably holds its value, most of the rest not.)
Still, it looks to me like Tesla is deducting too much for mileage. Based on what we know about actual deterioration with mileage. Don't we have some people on the forum who have put 100,000 miles on their cars? What condition are they in?
I looked at cars.com; the cheapest listing is $44,500, but that's for a 2012 S60 with 30K miles on it. The larger battery seems to hold its value, and to still account for a solid $10K difference in listing prices; it seems that it hasn't depreciated much at all. (This does not surprise me, since so many people are concerned about range.) The cheapest 85s start at 75K. Maybe some cheaper than that have sold, but probably not much cheaper. There seems to be no real loss due to mileage unless the mileage is *really* low; the prices seem to have very little correlation with mileage. There seems to be a substantial loss due to age, which is probably due to more features being present on newer cars.
I'm going to make the radical assumption that most options other than the tech package and the 85 are essentially worthless on resale. If so, this still means that the $67K offers on 85s would give Tesla a solid $8K profit -- *minimum*, assuming that CPO has no value to buyers over private sales. I think Tesla's being overly conservative. Maybe they're worried that the bottom will drop out of the market when the "D" model with autopilot comes out, but I don't think it will. Some 2013 Model Ses are still clearing $90K on the private market, so I think the older Model S will continue to be attractive at $75K. If Tesla wants to make a impact in the CPO market, Tesla needs to lower its profit margin target for CPOed cars, and raise its offers on 85s to be over $70K.
On the other hand, here's a thought.
It's possible that Tesla would *really prefer* that you go to a used car dealer. Tesla's been fighting with the dealers' association, partly because Tesla is making their new-car-dealer business model obsolete. If they can go into the used car dealing business, it offers them a graceful way out; if Tesla proceeds to dominate that too, then their businesses are truly dead.