Owners/service Manual problems of the 2009 Nissan Murano

My 2009 Nissan Murano locks on rear doors for both passenger and driver side started failing intermittently and I could only open them by reaching in from front and manually flipping lock. Now they are not working at all. I brought them to my service mechanic and he quoted approx. $500 for each! I don't have that kind of money to put into this car. Recently I had my elderly parents visiting and realized how dangerous it was that my mother could not get out of the car on her own as the rear passenger door won't open from the inside. But when I "alarm/lock" the car, the doors will still open and the alarm will sound. But there is no safety of having locked doors the driver side door still works but there is a miserable rattle inside. This is the most annoying, unsafe and poor quality problem I haveever had with a car. And it is even more frustrating this is a common problem that has been happening for so many years. I was planning on buying another Murano, but now reconsidering and may go back to Honda or Toyota.