CG 125 2004-06 model outside no will cost u arround 40-45K depending on the outlook and engine condition.,.. i suggest dont buy outside of karachi no coz it will give u headache registring in ur name. especially punjab no bike, also authorities will rip u everytime they stop u, u have to give atleast 50-200 in bribe to get clear...
karachi model on the other hand will cost u 5-10 K more but it will be much easier to get it transfered to ur name and if u take articulate measures, u will be safe from snatching.. however it is a major issue still with 125s, especially honda...
they will cost u a moderate amount in maintainance and running... generally 125 give 40-45 average if well kept and smoothly driven,, however if u grunt the engine alot,, do wheeles, do frequest fast pickups and drive recklessly, the petrol average will drop considerably alongside the Oil change, which u then have to do at 700Km...
maintainance will also cost more,, u will have to take extra special care of clutch plates, gears, breaks, spoket, tappits etc..
if u do want a regular usage bike.... 125 is good choice but only if u drive it sensibly and keep it at 1 hand,,, multiple ppl using will ruin ur bike...
If i advice, i may suggest u take a look at suzuki GS125/150 as an alternate,,,
whatever u do,, dont buy any other brand 125(china) as it will only last 3 4 years max,, then u have to spend alot to take care,, also its not as pleasureable as HOnda...
cheers