So we've discovered here that a private sale price is higher than a trade-in value? It has always been that way, this is nothing new. Car resellers don't work for free.
Another lesson, new cars depreciate fast. Well, nothing new here either. A new car that drives off the lot, loses approximately 2 years worth of depreciation, which is 25-50% of its value, depending on which car. Think about differently, let's say we look at $100K Model S. Say it costs Tesla $70K to produce one (not including R&D and all the other overhead, because they are irrelevant for example as they are fixed total cost). A customer after a month of ownership want's to return it, so Tesla is facing a question of how much is the car worth to them? They can make a brand new one, custom color and options, for $70K, so obviously the car with fixed options and a month worth of use (and not eligible for new EV rebates) has to be worth a less.
Value, or worth, of a car is always what you can get someone else to pay for it. There is no absolute or somehow "fair" value. If you can't find a buyer for your car for a price you want, unfortunately that means your car is not worth that much, no matter what you read on the internet or what you feel the value is.
So, if you want to prove to yourself you car is worth more than offers you are getting, find a buyer for more, make sure you add to the price the cost of selling it too, including any seller costs and of cost your time. If you think your time is free, then next time you want to trade a car, offer to work 20hrs a week until the car is sold for free for the dealership you are trying to trade the car in to, you might get a higher offer, but you''ll have to work washing cars, etc.
