How much is the labor and used parts price for new air conditioning unit?

My car was running very loud and we realized the serpentine belt had been
broke so I bought a new serpentine belt  And when we put it on the car would
not turn on when you take it off it starts up and runs without the serpentine
belt on I was told it was possibly in frozen air condition unit does that mean I
need to call a junkyard and get a used air condition unit from a car at a
junkyard or do I buy something like that brand new how much are we talking
should it cost to fix something like this and how many hours of labor are we
looking at if you could help me out I’d greatly appreciate it