No way man, that guy's been smoking hash!
Its not that difficult to replace the tumbler. the instructions I believe are her on the forum, or purchase a Bentley Book on the car. The car is 14 years old so it time to get physical with her now. The value on the 400E is low enough that taking the car to the dealer and paying top $$$ really does not good business sense...The job is a snap. You'll have to get a dremel to cut the ring off the tumbler because the key needs to be in position 1 in order for it to snap off....and since the key will not turn...catch 22. BTW the ring is ALMOST indestructible to all things except a dremmel. See past posts on this topic. My advice...Just Do it!....What have you got to loose. It takes about 5-10 minutes to get to the entire lock assy.30 min or so to set up , dremmel, moan , *****, and complain about who the #@%& design this thing this wayand then remove th old part. Then about another 30 to install the new part and package everything back up. If you order one, get two keys.....Not that you'll need one for the next time(14 more years, mine will be long retired) but it'd be good to have a spare in case of loss. Good luck