Need some input...How long doest it take..
 

and how much does it cost to replace receiver dryer and expansion valve and recharge the AC system 95 E320?

This morning I brought my car to a local MB shop in Northern Blvd Queens New York to fix the AC. I told a lady there that the AC is not that cold and I told her to find out what the problem was and tell me at work before doing something because I had to leave the car at the shop.

Before I left she told me that it would probably be a leaking or I had to replace something that was broken and would cost me around $280.00 for the parts.

When I picked up the car I was shocked because they charged me $638.63. I asked the lady why it cost that much. She told me that the labor to perform the job was 4 hours and they needed two people to do the jobs. I looked at the sheets and find out they charged me $356.00 for 4 hrs labor and $282.63 for the parts.

I do not mind paying that much but I really doubted that they really spent 4 hrs to install receiver dryer and expansion valve and recharge the AC system or maybe I am wrong.

Does anyone know how long it takes to do that particular job? Does it really take 4 hrs?
I would really appreciate for any input.
Thank you.

I have no idea what the "book" is on this job, but I can see four hours easy.

You have to locate the problem, then evacuate the system, repair the problem and possibly replace items like the drier (which should be done whenever the system has been open to atmosphere, such as with a large enough leak). Then once all that has been done you have to evactuate the system again and draw a deep vacuum, like 29 inches HG and hold it for a time, then recharge and oil the system. Plus test the system afterwards. It all takes time. Sticking another tech on the job likely saved an hour or two labor charge.

Just this DIYer's opinion.