gnychis, I feel bad for you! It sounds like you're getting bad news in each reply. But I may have more:
I've spent the past 6 weeks or so looking at used Model S ads on Autotrader, CarGurus, eBay Motors and TMC. I'm looking carefully since I'm actually shopping for a car, but am not in a hurry to buy, so I've learned quite a lot about prices and, as a prospective buyer, am probably qualified to represent buyers and offer some points:
1)
Expensive options don't count for much. When I'm looking to buy a used car, there are core options that I consider valuable, but most are just a bonus if they happen to be included in a car that I like. Sunroof, tech package, battery capacity? They're core options I'll pay for -- important. Paint protection, premium wheels, premium interior, premium sound? They're bonuses -- not important, but if they're present, great. In short, high dollar options at the time you ordered the car new may not pay off or differentiate very much in the used market. This generally applies to aftermarket things like a premium center console, too.
2)
The 70D really will drag down prices on used 85 kWh cars. You can be sure there will be lots of buzz about the 70D once the cars are actually on roads. You'll see YouTube videos of people showing off the crazy (albeit not "insane") acceleration and it'll be all over the interwebs. Being the lowest priced new Tesla available, any prospective buyers of a used Model S will look at this popular new kid on the block as a good option. Sure, 70 kWh is less than 85 kWh, but if a car has lots of miles on it already, buyers will assume the battery pack's range has diminished (true or not) and a brand new 70 kWh pack feels about the same. So yes, my opinion as a used Model S shopper is that the 70D will be a big downer for anyone selling a used Model S.
3)
Random point about the 60. I know you aren't selling a 60, but wow. I can't explain it, but the 60 kWh cars I see for sale are almost always priced as high as comparable 85s are. I don't know what they actually end up selling for, but it's incredible that people are asking so much. My only guess on this is that, in general, the people who bought a 60 in the first place couldn't afford an 85 and therefore can't afford to let it go for less than top dollar. I suspect there are a lot of 60s sitting overpriced for sale, dropping in value all the while, and at some point in the next few months (probably related to the 70D's release again) people selling a 60 will be forced to drop the price significantly. We'll see cars selling in the mid-to-high 40s this summer. As for the 40 kWh version, these are so rare I've only found one for sale, and it was nearly as expensive as an 85 at $63,000, but it was at a dealership, so...
4)
Dealerships are screwing up everything. I know this is a popular statement among the Tesla crowd in general lately, but when it comes to used Teslas it's as true as ever. It's painful to read through a sales listing for a used Model S being sold through a dealership. They emphasize the wrong things (Color display! Heated seats! Cup holders!) and completely omit important details like battery size, supercharger enabled or not, air suspension or springs. They list features that are obviously not available (Chrome exhaust tips! Rotary engine! Automatic transmission! Gas sipper!) So you can be sure that they are almost never competent enough to price the car correctly. You can find a 2012 S60 with 30,000 miles and few options priced at $75k, which is ridiculous. This may help keep prices up, but mostly it just confuses and annoys potential buyers.
So, all that said, I'll offer you $48k for your car, gnychis.