Dear Asad,
Although sechond hand cars are useless to buy, as discussed on this forum very frequently they have hidden prizes for you! go for any other NEW car within your limited budget. But if u still insist to go for a margalla! yes its a nice car i would say its the best in 1300cc carbuerator.
But do check the following b4 u go for one: Normally margala may have problems in the following equipment:
Tires, suspension, Body (in terms of rusting), get it check by a mechanic for accidental checkup. Engine noise and smoke. take a test drive and listen to its axle noise (you can check this by turning the steering to right and left at its extent and then accelarating. Look for mileage and check wether the engine has been overhauled. A/C performance and ventilation knobs, window's closing and opening mechanism & door hinges.
These things simply won't just let u know the condition of the car, you can use them to bargain with the owner too!!
Best of luck! on your decision
Akif