CAR WOULDN'T SHIFT INTO PARK AND RELEASE

What is your question?

My girlfriend had trouble shifting her 2004 Mercedes E320 out of park. When she tried to shift back into park, the shift lever would not go into park and the the ignition key couldn't be removed. The dealer forced the shifter back into park but now the car is non-functional. The dealer said this often happens if something is spilled in the shifter area (not the case) and that the part alone is $900. She has had several problems with the transmission and complained of hard shifting out of park 11,000 miles ago but the dealer said nothing was wrong. What are the issues and fixes?