Dude, try a junkyard for an IAC... or ask here on the board. $250 is a ripoff.
The idle screw is always in the same place on every car... it is used as a stop on the throttle cable pulley on the throttle body. There is a little right angle at the side it stops on, and the screw is behind that, in another bracket. It's very hard to get to, and very hard to adjust as even a teeny tiny turn will make drastic changes. You really aren't supposed to play with it.