i bought a used 2018 model last year with ~80k miles for $~12k after discounts and rebates. for me, this reflected the best value car i could buy at the time, especially given that i have free charging available to me. i also appreciated that i didn't need to worry about many common failure modes on used ICE vehicles, however it does have the expected battery degradation.
I just finished replacing the battery pack heater on my 2018 Model S. I’m at ~130k miles, and it went the other day preconditioning before Supercharging. Tesla charges $800-$1000 in labor to do it, but I’m comfortable performing the high voltage isolation and swapping it myself for $200 in parts. Moral or the story is even if you get them cheap, be prepared to spend a bit if you can’t do the work yourself. The 3 and Y are more robust around thermal system reliability (heat pump conditions both battery pack and cabin, for example) but the complexity has a cost regardless.
