If you mean the A/C compressor, that is not too bad. The charges are for disposing of refriegerant, testing for leaks as the sytem must be leak freee and new oil and refrigerant.
Make sure you are careful with the connections and pipes. Before driving it make sure you addd new oil and the proper amount of refrigerant before running as not putting in the proper amount of oil and the right type will harm the comppressor. I have attached the two common places to find A/C specs and if you look on them you will see amounts of refrigernat/oil and types.
Images (Click to enlarge)
Tuesday, December 18th, 2012 AT 2:11 AM