So the corrected 60/120/180: $23k, $25.5k, $28k.
And true, it will be worth something after 10 years or so, figure $10,000@60, $5,000@120, $3,000@180 but it varies vastly with the brand, mileage, and condition.
Corrected again: $13k, $20.5k, $25k
Damn, looks like it's close to a wash after 10 years. But, consider that the used car is a Lexus with heated/cooled seats, leather, nice audio, power seats and windows, automatic wipers, etc. etc. and the new car is a base model Toyota Corolla.
Plus, the use car will not be worth zero, hopefully, after 10 years. I guess 60/120/180 would be something like $3k/$2k/$2k:
So for the used car: $9k, $15k, $19k
So a bit ahead again.
It looks like with these napkin calculations the $20-25k mark is the break-even point at around 10 years. So any new car more expensive than that is going to be more costly, obviously, relative to a used car.
Well it was a fun thought experiment.
- you're including interest for the new car but not the old
- you're ignoring the residual values of the cars at the end of the 5/10/15 year periods
[edit: and the "cost" of that 3 year/2% loan is $623, not $8073]