Well... to answer ur Q, I must recommend u to start walking, rather than hopping on a bike.
But u insist on cycling, then go for a mountain bike with maximum gears as they say it. Mostly u will find bikes of Paki or Chinese origin.
But if u go for western bikes which r hard to find.. and u get one then the cost invlolved is too high depending upon how much u can afford.
Western ones Cost around 15 K to 20k or more.
Whereas local or chinese cost 8000 Max.
Costs mite vary...
Bikes r available in Blue area ISL and Saddar pindi.