Since A/C is not blowing cold, I took my car to a local shop. They discovered a leak (using Dye) around the expansion valve. At first they called this the expansion block and were quoted over $700 for the part at the local Mercedes dealership. I believe that the dealer must have quoted them a new evaporator coil.
Anyway, I purchased from fastlane a new expansion valve ($25) using the part # that was on valve. I also ordered a new receiver/dryer ($35) as my CD's show that this should be replaced as well. I was thinking about replacing them myself, but will probably just take it back to the shop to have them do the whole job (including the recharge).
Is there anything else I should concern myself with?