why don't you find out how much it cost for a working one... Then get an estimate how much to spend on that car to get it roadworthy... Check oso on the chassis condition whether got rust or not.. Can be anything between 5k to 10k for the mechanicals... or more..
Then calculate backwards to get estimated max you u should for the car... Of cos, if can get cheaper, better loh.. Cos u may have to spend more for wear and tear after so long not being driven...
At the end, you'll probably realise it's cheaper and better to pay for one which is running condition... Unless u can get that car for free... and just spend on restoring it...