I strongly suggest you to stay away from this business. The car business is full of thieves and shit people. This bijniss requires you to sell cars based on lies and also sell your emaan. There's no such thing as a cheap car in Pakistan, jab sab sai ho gaari me tou koi sasti kion beche ga?
Anyways, if you still want to do this business, i'd suggest to get a completely genuine car (islamabad number preferred) because pakistanis drool over original and faded paint. Look out for any accident history in said vehicle and make sure it's mechanically sound. Lahore number works too but make sure you have the complete original file in hand and a biometric issued to your OWN name.
I still suggest to do something else. Best of luck