I buy new. I buy what I want and if possible try to factory order, so I get what I want, not just what's there. I pay cash, unless there's a good deal, like 0 % interest over a good number of years.
I think carefully what exactly I want, in a vehicle....as I plan to have them for a long time.
No impulse buying.
I buy extended warranties. I rust proof with Ziebart. I maintain by the book.
I drive my vehicles for years. One vehicle for 21 years, another for 14, another for 10 years. I usually have anywhere from 2-3 vehicles in my parking lot / garage at any one time.
When I'm finished with them, I feel I've got my money out of them.
I don't worry about depreciation as the way I do things, it's not much of a factor.