Mercedes Benz repair: my EXPENSIVE car prob., spark plug wire, hose clamp

Question
I havea couple but I recently spent $2,000 to fix my benz I just want to know if the price sounds right. The trouble shooting codes I was given were P0300, P0305,P0303, & P0304 misfire codes. so i replaced the spark plugs and wire set's as they recommended. Then the mechanic at the shop I had the car at said I waited a week to ok the work on the car so when they went to work on the car they found that it would crank but not start. My key had been damaged it was obvious but I did'nt ever have problems like that before they did. So they advised I spend $200 more and replace it cause it was needed. There excuse so I bought it.  They replaced the key and my car that I drove into the shop would not start even after the new kew,spark plugs, and wiring harness's. They then traced the problem to a frozen fuel pump.So I replaced the fuel pump.Then they say it started.It ran good for Awhile they said then started to act up.They rechecked and such & said they were ok.They thought it was low on fuel so they checked the volume.They say this is when they noticed that there was a lot of water in the gas.They had me ok it to drain the tank and put in new gas and an additive to help get rid of any remaining water.They said the water problem might continue to cause a miss for awhile but should clear up eventually.There report says this and at the end says customer understands this otherwise we might have to pull the tank.What that means?? my reciept says 12 spark plugs@$14.50ea, 1 spark plug wire set-$260, key blade-$37(i didn't get this if it's the medal part of the key but i payed for iyt whatever it is?)Also 1 pump fuel $348, 2-BG 280 Fuel Drier's@$16ea,fuel gas$30, BG gas additive$26, 3-hose clamps 4H@$1.20ea, 2 hose clamp German 08-12@$2.00ea, 1 Hose clamp German 16-25@$2.15ea, And finally a fuel filter $132.00 oh yeah and $200 for the new key. Does this sound right?

Answer
I hate to tell you this, but it sounds like they took you for a ride. With proper diagnosis, trouble code causes can be found with little effort. It really sounds to me like the mechanics were "shotgunning" the car, which means, they are just throwing parts at it in an attempt to fix it without properly diagnosing the vehicle. The problem with the key sounds like something they caused that they decided to pass off on you. If I were you, I would take your labor reciept to MB dealership and let the service manager take a look at it more closely and give you his advice as to what should or should not have been charged to you.