[el ess A]

GM compressor is p/n 23374616. List price is 541.65. Can get them for around 340-ish plus or minus nearly anywhere if they got 'em.

Expansion valve lists for 141.50. GM part number 92229746. Around 80-100 plus or minus generally.

Receiver/dryer is GM p/n 92229743. List price of 152.43. Around 90 plus or minus on average.

So even if you got the GM parts for nominal prices, you'd be pushing 600 if you bought them and around 900 if you let the service place buy them. Like fencing, usually doubling the cost for the parts and having someone else do it. So 1600 isn't really out of line. When you let the service place buy the parts, you normally pay full ride on them. Just depends on their warranty.

The 68683 number is a four seasons number. I'm not sure if that's a NEW compressor or what.*