WOW! Before I go any further, I am aware that I am referencing some older posts, but I just saw this thread for the 1st time and had to respond.
No, Tesla owners are not Dumb to spend more on their window tint than you did on your minivan. You said you didn't care about anything other than making the windows darker. Typically, Tesla owners do a LOT of research before choosing a shop and the care a lot about more aspects of the film than just making the windows dark. They care about the level of expertise the film is installed with. They care about blocking as much Infrared Heat and UV as possible. Most of my Tesla owners actually don't want their windows to be super dark. They like to be able to see easily and not look like they are hiding anything in their cars.
You could not be more wrong about the reasons for window tint costing more being just clever marketing and gimmicks? Seriously? I've been a window tinter for almost 20 years. It is a skilled trade, not just a product. Just like cars, material has evolved and improved a lot in the last 20 years. You need to know more details about these car than ever before or you'll cause major damage. You spend $70k+ on a car and want to cheap out on the tint. Maybe you should have bought a cheaper car or just buy the tint and do it yourself if you don't think it isn't that hard. It takes me 2-3 hours to tint a Model 3, from start to finish. For a Honda Accord, a little over an hour.
When you remodel your kitchen with all new appliances, lighting, and flooring, would you get new formica countertops?
Suntek Carbon is a cosmetic film and only gives UV block and privacy. Barely helps with heat block at all. A Model S has it's own challenges but still doesn't take as long to tint as the 3. Is it "unnecessary" to actually get a more energy efficient film? If you don't care about blocking heat, then you're right.
We now sell Ceramic tint exclusively at our shop because of the heat blocking properties and visual clarity.
We do need to stock bigger (60 inch) rolls for JUST the back glass of the Model 3. ALL other cars require 40 inch rolls or smaller. We stock 4 different shades for our Model 3 clients. At over $1000 per roll, per shade, I have to now spend over $4000 to have the options on the shelf. Compare that to "standard" (non-ceramic) tint of 15 years ago, you could get "decent" film for $150 per roll and be able to tint nearly any car on the road. If your spending limit is $250 for a tint job based on no facts to justify it, there are lots of lower end shops that will be happy to take your money. Good luck. Maybe those shops will sell you some chrome spinner rims and gold plate your emblems too?
I am constantly shocked to hear people that get new cars, especially higher end cars, that seek the "cheapest" deal. Why have a nice car and only aim for "decent/good". Being frugal is one thing, but don't try to justify being a cheapskate and create these theories about the window tint films not being worth it. If you can't afford it or can't justify it, then just don't get it done.
Lastly, Ceramic Films do not interfere with cell phone, GPS or any other signal. Metalized films that was developed 15 or so years ago might have interfered, but it was rare.