Neither. Search the internet, Ebay, cars.com, etc....
If you buy one from Tesla, you get only their warranty 4 yr/50,000 miles with no chance to extend it. There are plenty of used Tesla's out there in this general price range and those sellers WILL NEGOTIATE. The advantage is, the car is still under warranty, so if it has some minor issues, Tesla still has to fix them at no cost. So a CPO has no advantage over a non-CPO from Tesla since they're all still under warranty. With a private party sale though, you'd be able to extend the warranty another 4 years / 50,000 miles from the 4 year / 50,000 mile mark on the car, not the day you get it. So if you find a 2014 with 15,000 miles, you'll have the factory warranty for free for 2 years, 35,000 miles and a chance to extend it to 6 years, 85,000 miles versus only getting 4 years and 50,000 miles on a CPO.
The 2014's have better battery chemistry, so you definitely need to figure out the cutoff VIN for 2013 when it changed. Early 2013's are priced much lower, even by Tesla, for this reason (straight from Tesla's mouth). In the 2014 you showed, you give up the very important Air Suspension. At least for me, it was a must have. The ride quality is arguable, but if you deal with any types of steep driveways, it's well worth it to not scrape up the front or rear of your car by dragging.
I bought my first Tesla used and was very happy I did. Got a better deal than anything Tesla was offering at the time. I extended the warranty. I upgraded to a 2015, but the extended warranty added a ton to the resale value.
Can't really go wrong either way, just my opinion that you can get more from a private party sale than you can from Tesla.
For example, just ran a quick e-bay search for you. Found this 2014 with only 9,800 miles, same color you wanted. Far less mileage. Asking $68,500 and over 20,000 less miles. Can certainly offer less for it. Tesla, you pay what they list or you don't get it. Just saying, explore all your options.
Tesla Model s Sedan | eBay
This week is a light week for Tesla's on Ebay, likely due to the holiday. Only 34 listings. Usually there are around 60. So give it another week and keep checking. Unless you absolutely can't wait, I would take your time. I took a month and a half and bought my car for $11,000 less than lessor equipped cars Tesla was offering at the time.