AC Compressor locking up intermittantly?? Help?

[willrev]

Friday, I pulled out of the drive way in NC and it was 80 degrees. Switched on AC and heard the belt start squealing and car bogged down badly. Immediately cut off the AC and all was fine. Figured the compressor locked up.

Today is Sunday and I accidentally forgot and turned on the AC and it worked. But I cut it off quickly because I did not want it to lock up again.

Can an compressor lock up intermittantly. The compressor has been chattering for over a year now when I start the car.

I was quoted $295 for a new compressor, $70 for the receiver drier and whatever the labor will run to evac and recharge the system.

Any good sources with low prices on compressors? I want to go new, not reman unless someone has a good reliable source.