If you care are about cost, you buy a used car -- not a basic model.
If you buy a new car, you're already paying a premium. If you're willing to pay a premium, you were probably not looking for a basic model in the first place.
Edit: I'd be interested in a more basic car, even new, not because of cost. But because I don't want my car to be a gadget that is outdated in 3 years.
I'll buy a new phone for the fun of it. Not a new car. So don't put a tablet in my car :)
Sadly, I'd suspect a tablet is actually cheaper than physical buttons.
If you buy a new car, you're already paying a premium. If you're willing to pay a premium, you were probably not looking for a basic model in the first place.