If you can't source parts in this day and age it's not the car's fault. Anything made in the last 30yr you can readily get service parts for. What you can't get at the parts store are interior trim and non-wearing suspension items that are specific to a narrow range of vehicles (also true for new cars) but if you expect to keep the interior of a bottom dollar car in tip top shape you're out of your mind. The internet makes finding everything that isn't a normal wear item super quick and easy but you're gonna have to wait 24-96hr to get it.
$400ish (get lucky on a $250 "ran when parked" car, pay by month for insurance and live in a low tax state) on up.
>AAA says car ownership costs $8,558 per year
They say it costs that on average. That's very different from the floor or baseline cost which seems to be what you're implying.