There is provably over $300 in parts and the rest labor which isn't bad. If you waited till summer the price goes up dramatically. You may have extended the life of the old compressor but I don't know for how long. It seems like our compressors only last about 100k miles any way. I might keep your guys on a list of trusted mechanics as many are seedy.
Mine clicks until the engine warms up. I better look into that.