Sir you can get new Cultus for 1.1M on road after taxes and registration.
Chevorlet Joy has near 0 aftersales and parts availability.
Alto was EOL on 30th June 2012 when EURO II was enforced in Pakistan (For new cars and motorcycles made in Pakistan only).
400K will buy you a 2001-02 Cultus in good condition.
Cultus G10B engine is more economical and responsive than Alto F10A which was an ancient design.
The overall driving and interior is also far better in Cultus compare to Alto & Mehran or any kei car.
Used Santro / Spark / Vitz etc are good only as long as they do not break down.
If you want something with modern technologies you should consider a Daihatsu Mira e;S 2011 model which will also set you close to 900K. Just prepare to pay 18K (nearly twice the price of new Civic or Corolla) if you need to replace the headlights
You can also get a W202 or E36 in Pakistan for 800K but you will end up spending half the car price at its maintenance.