^ You are actually limited by your own choice.
First you say that you want a Sporty Bike, something like a YZF R125, then you are worried about:
1. Its maintainance
2. Its After Sale Value
3. Lack of Sound
What makes you think that buying Yamaha R125 will NOT give rise to these issues?
Dont you think that its maintenance will be as expensive as a Suzuki Mehran.
What makes you think that its after sales value will be as good as it will cost you New?
And Hell, what makes you think it has a good sound? Do i need to mention its still a "125CC"? Its upto the Muffler to make good sound.
Anyways ... Ravi Piaggio will be a much better choice if you want a Sporty Look.
You live in Lahore dude, so dont even sweat about its Maintenance and Spare parts availability. There are Plenty of people living in Lahore, are happy with it.
And if you ask me, its the one bike available in Lahore, which actually has a Modding Capacity (looks wise)
About the sound, with an Aftermarket Silencer ... You'll be amazed HOW POWERFUL sound this bike can produce.