Water pump

I just logged on for the first time in many months. I cannot believe that the membership went from about 1800 to now almost 5000 since I joined. Well actually I can tell, but still in awe none the less. I am noticing many improvements to this site and posting convenience. Kudos to the web adminstrator.

By the way, I just spent around $600 to replace my water pump on my 300. Why so expensive? Is there some gold shavings in that thing? Why can't the pump be fixed, it always has to be replaced?

How many miles does a water pump and a radiator usally last in the two Benzs that I have? Had a small leak in the radiator while under pressure (14 psig) and had to replace that as well.

Thanks Guyz