Brother you can buy a 2002-2006 Mira for as low as 5 lacs here in KHi.
Mira For Sale In Karachi | PakWheels
The new shape 2006 onwards will be 6 lacs and above for 5 door versions.
Best thing is to buy from KHi and transfer to LHR if you want to save money.
New Mira is a LOT better than 10 years old used Vitz.
Mira runs smooth on highways and I had a 4WD 2008 Mira which regularly gives 18km/L on highway with AC. 2WD will give even better mileage.
AC performance and luggage space is also good.
At highway speeds of 80-100 km/hr you can relaxly cruise with just one hand on steering.
The car will start shaking after you cross 120 which is above legal speed limit in PAK.
Old shape Vitz is 4 cylinder and not very popular for fuel economy it will give you max 10-12km/l and parts are also expensive than Mira.
Just keep your car in proper shape and use a 50:50 HOBC blend Mira has much better drive and engine than Alto Cultus etc. Use proper Toyota OEM parts and fluids / filters etc to prolong car life.
Just make sure to insure or takaful your car as new Japanese cars could be stolen.