Pontiac Repair: 98 grand prix gt, grand prix gt, release key

Question
QUESTION: August 09' Car wouldn't release key and it wouldn't start. So I turned the wheel left and right (a lot) and played with the gear shift <at the suggestion of a friend> finally got the key to release and eventually car to start. Oct. 09' wouldn't start again. This time the gear shift trick didn't work so we replaced the battery. A couple weeks later it wouldn't start again. All that I hear is a singular click when I turn the key. The battery is fine... We also replaced the ignition relay... no joy. Several people have said it could be the starter. What else is possible?

ANSWER: could be the starter or the ignition switch itself.  with a helper turning the key to the run position when it won't start try tapping the starter with a hammer lightly if it fires the starter is hanging up

---------- FOLLOW-UP ----------

QUESTION: in which case i would need to replace the starter correct?
also, what's the ignition switch and is it an expensive replacement or fix?

and thank you... so much.

Answer
ignition switch is the portion that you put the key into to make the car start, it is attached with a wiring harness, labor to install is not too bad but the part is pricey.  If the car starts when you tap the starter it is most definitely the starter