In which city, province you are? As far as Islamabad is concerned you can get this number without any charge.
Only these numbers are issued after paying the prescribed fees and filling a rupees 20 form before you go for submitting application.
For 485 you can request while submitting the application docs at the window. If it is not available in the current ongoing series, the clerk may send you to the computer section upstairs where after checking in computer data official will write with pen on your file that number is available in next series and it will be reserved for you and you will get it after few weeks.
They call special numbers in Islamabad and here is the list and charges:
