A/c not working/ squeaking- 1998 Pontiac GTP?

[Saratoga]

I bought a 1998 GTP about 3 months ago. There has always been a slight squeaking from the serpentine belt and I figured out it was coming from the AC clutch/ compressor area after playing around for a while. About a month ago the air stopped working, only occasionally, where it will stop blowing from the dash, but will continue on the feet, even though it's set to dash. Whenever the air goes out like this the squeak stops. About a week ago it started squeaking to where it's about 2 1/2 times louder and got louder as I accelerate, but it stopped switching from the dash to the feet and back and forth. Yesterday it started blowing out of the feet again and the squeak stopped completely. It's back to where the AC blows from the dash but the squeak is back. If i turn the ac off the squeak will become louder. So to my questions; is it the clutch from the AC or the compressor? Why does the squeak get louder as I accelerate if it's an AC issue? Lastly, I found a clutch for $50, with a 1 year warranty and it's AC Delco, is this a decent price or can they be found cheaper and if it's the compressor will it save me enough if I go to a you-pull-it junkyard for it to be worth it? Any help is appreciated.