It will cost you from 12K to 27K.
All orignal toyota parts brand new with wooden kit will cost 27K.
Used motors for 88 corola, used channels required alteration at the time of fitting, old model buttons, local pannel will cost you 12K.
You can go to Saddar Rawalpindi there is a market behind Hera brothers in that market there is only one person who does power windows if you go to any shop in sadar they will call him so its better to go direct and get it installed at better rates.