Dude
For Price...Obviously city is more costly but it will be totally new i.e. zero meter
Maintenance....Accept it, local representation of the company and its spare parts availability is a big plus point..so city in this case as well
Durability....belta is a japanese and city is pakistani..Imported Japanese cars are more durable but used/re-conditioned..city will be new and belta will be used and you never know whats the treatment it had back where it came from..Still i am not taking anything away from japanese cars.
Fuel economy...city and belta both are fuel efficient car...but city is 1.3l where as belta you are asking for is 1.0l, so there is a difference. Nevertheless both are fuel efficient cars
Remember that if at any point you want to have cng installed on it as a contingency for multi fuel availabiltiy as well as cost factor....then city can be run on cng
Comfort...there is not a huge difference between both cars except that city has a little stiff ride on bad roads..
Safety....belta takes the lead as have airbags..one wishes that our pakistani companies should be offering them but they do not due to many reasons..
So, what if airbags come out and you need to fit them in...there is not a local, easy and cost effective solution for that. Even though death is inevitable, airbags are a good feature..but city also has good safety features.
Hope it helped....go for city