There's a shop where you can find 45-50cc petrol Scooters and some made in China electric scooties. it is near Kamran Market. But I'd say if you can afford to spend more, try to import Honds Super Cub 50cc. it's cheap, the hardest machine suitable for pakistani roads and consumption is 110kms/liter (ONLY 0.55 Rupees/liter) however, you can't cross 50kms/hr.
otherwise, go for some like Hero.