well i am not sure about it exactly plz call mughal autos at 5950327 and talk to salman . he will give u the exact rate
and as for ARSHAD electrition.i know the guy very well . he might be the best in electric work but he is the most expensive electrition in whole rawalpindi he charged me 4000 just for a digital meter fitting and to get gauges in order.i am not sure he will fit power window of surf in 7k
here are the few thing u need for power windows and thier estimated prices
3 power butttons and one master controll button of surf 2500
4 door handels of surf 1500
4 power machines of surf 3000
4 power lock of either 88 coolla and surf 4000
1 full wiring of surf 2000
now u do the math and add a coupe thousand for misc stuff
if u go for only 2 front power then the rate might be in 7k range but i am pretty sure 7k is not the rate for all 4 power windows
give arshad a call and then do let me know weather i am right or wrong