Phil is a great guy. The 10P17C brand new w/ clutch for $550 is a bargain. I would call him again and double check the price of the clutch alone, though, as they usually aren't 70% of the price of a new compressor w/ clutch (more like 40% most of the time). Make sure w/ Phil as there may be some miscommunication on this.
The clutch bearing can be replaced by itself if everything else in the system is working well. Here is an article on the 10P15C(little brother to your 10P17C) that shows how to get to it and you can put in a new bearing and thats it.
http://www.pelicanparts.com/techarticles/911_Nippondenso_rebuild/911_Nippondenso_rebuild.htm