The title of this post is technically incorrect – my Model S is actually 10 1/2 years old. I have lost quite a bit of enthusiasm for both posting and Tesla in general so a significant delay occurred before writing this post.
For newer readers to this blog, I started my electric car journey with the Roadster back in 2009. I ‘upgraded’ to the Model S in 2013 primarily for an extended range and the ability to supercharge. I took the Model S on a cross country trip in 2014 and have enjoyed many long trips using the superchargers primarily within California.
I thought a quick summary of my experiences would be in order including all costs.
Battery Life
The car now has 127,000 miles with just a little over 200 miles of range left. The range has dropped significantly since the car was new. The range is still fine for the majority of driving but is a little limiting for longer trips.
Cost of Ownership
Over the last 10 1/2 years I have spent about $19,000 keeping the car maintained with $7,000 of that in tires. Due to my serious problems with my tires, I got a free extended warranty which covered quite a few items along with a few ‘goodwill’ items.
Straight insurance rates are a little complex when bundled with a second car and home insurance, but simplistically averaging $800 a year for a total of $8000.
Since all charging occurs at home with a long paid for solar system combined with free supercharging, no energy costs are included, which is unrealistic for the majority of owners.
Purchase price including tax was $101,000 for a total of approximately $128,000 ($101,000 + $19,000 + $80000) in expenses.
The current resale value from a quick look online is around $20,000, reducing the costs to $108,000 resulting in a cost of ownership to be about 85 cents / mile ($108,000/127,000 miles).
Battery
I am a bit worried about what to do if the battery completely fails. I have heard a variety of quotes for replacement costs of batteries that range start at $14,000 with a remanufactured pack from Tesla. A company in Arizona will sell you a refurbished one for $5,000 but you have to ship the car there.
Next Car
What will be my next electric car when the time comes? I ironically would ideally like some contradictory features: more range, 4WD or AWD, and a smaller physical car. I also prefer for the next vehicle not to be an early adopter and let someone else work out the kinks of a new car model.
Although initially I was enthusiastic about Tesla, my enthusiasm has waned significantly. I don’t like interacting with service only through an app, and I am not a fan of Elon Musk.
TESLA OWNER 
I’d be surprised if you’d get 20k for it with the feature set and mileage on it. For many a used 3 would be a better option. Other than the Elon part your needs seem to match a 3 or Y especially if road trips are in the picture. Maybe in a few years when NACS is used by more companies things will change but non Tesla road tripping is pretty painful still.
Hope you get to keep enjoying it for a good time longer.
I only did a two minute search for prices on used Model Ss, so it was just a ballpark. Around here I know it is really hard to find any cars 10k or under that are remotely reliable. I’m just not interested in the 3 or Y, and would rather keep the S until something interesting comes out or it just is too costly to repair. The S is just fine and has aged really well, and I still have no interest in autopilot but AWD would be nice for the one or two times a year when I see the snow.
My experience is somewhat similar on many fronts. I purchased a 70D in May 2015. I currently have 160k miles. I think the battery has held up reasonably well – I get about 215 miles @ 100% charge vs 240 originally, so around 10% degradation. I haven’t kept as detailed cost records as you, but fortunately I have not had any major repair bills and seem to get good mileage on the tires. I charge mostly at home and have free supercharging for road trips. My insurance is a lot higher, but I live in CA. The car still drives great, but I am ready for something new. I too am struggling with the low resale values, which are causing me to hold onto the car longer. I don’t have a huge problem with Elon, but I won’t buy another Tesla. I find the interior finish too inferior and cheap vs say a Mercedes or BMW. And I too hate interacting with service through the app, although as a former Tesla Solar owner (a previous home), the vehicle side is actually a better experience than the solar side.
Your battery is in great shape! You have a smaller pack than I do, more miles driven but more range! I live in CA also but I keep my deductibles super high and combine it with auto and home. My ICE vehicle uses CarPlay which is far better than the Tesla interface for music/books/podcasts but other than that I’m not too picky about the interior. I have heard really negative reviews about Tesla Solar here too. I’ll probably keep this car until it dies in reality and it makes no sense to fix or something interesting comes up. thanks for the interesting comment.