Replace cable or new finder?

[southernboater]

I have a Lowrance M56 gps/finder on my pontoon. The unit is about six years old and is used in both fresh and salt water. The cable which connects to the actual unit is corroded beyond repair. I can get a replacement cable for about $25. I noticed a new transducer is around $85. I am wondering what the average life of the transducer is in order to decided whether to repair or get a new gps. I only get out 1 - 2 a month and would only need a good "basic" system. Any advice is appreciated.