Cheers man,a few guys on here remember me when I was a noob not too long ago,so ya gotta commit ya self to get anywhere with cars.
200 is way exxy for just an iacv,I would personally put up a wtb thread on here and hopefully somebody has.

Have u tried taking the iacv off and opening up the gap with say a screw driver?just a tad,not too much.

I have found they get a bit stuck.they can also become loose or stuck completely open.

I haven't read into it but there's a magnet in there plus the sensor which together regulate the air gap for idle (iacv).

With the gap opened a tad,u can then turn the idle screw back.

The idle/air screw is just air.not like the old carbys that has an air/fuel mixture screw.if ya touched that thinking it was the air screw,...good luck getting it right again.yeah,so don't be afraid to play with that whenever you want.

Keep us posted.