E420 "97" Key Locked won't turn
 

I have a 98 e420 with a metal key, don't see any chips just tumbler cuts on each side. I have read several postings and i am still confused...can a above avg DIY fix this problem. I assume the switch needs replaced. talked to dealership they say 900.00 plus dollars 2 or 3 special tools,special cutting tool..... they said since it wont turn to on position they will have to cut it out, order new switch and keys(5 to 7 days to get keys cut)....crazy thing, i was trading car in for new hybrid next week...Can anybody help? I would like to get by long enough to trade

You could try vibration
 

Stick the key in the ignition and with any vibrating tool like an air or electric sander, or even an electric razor or hair clipper, hold it up to the lock and vibrate it and gently try to turn it. If you do get it to turn then you could start the car or attempt to pull the switch. If you shut the switch off, you have no guarantee it will turn the next time, but it might!

Spray some dry graphite lube in the lock (if you can get the key out). Should be able find some at an auto parts store or hardware store.

Do you have a spare key? Have you tried it? Use whichever key has the sharper cuts, and wiggle the key back & forth while moving the key slightly in & out. Also, make sure there is "slack" in the wheel - could the the steering lock causing the problem.

tried most of your suggestion except the vibration with sander, i will try after work
thanks