The cost of Raymarine, new digital radar with a small Chart plotter Hybrid Touch screen is 2,000 bucks (WM on sale). Digital consumes much less power(1/3) and is also solid state, no internal moving parts. I had a C80 on my Bertram SF spinning around with analog radar, and I don't see much difference, although many more options such as a weather setting, coastal, harbor and open sea settings...
The Bertram had however 2 ,14" very, very expensive MFD screens... which made everything look better! Back then it was $30-40K in electronics... and not as functional.
A larger Chart plotter is nicer and almost a need. And that will cost you another 2K (12", non touch), but then you have one at nav station and another at helm, which is really nice...plotting your trips in the evening or rain while inside.. The small screen will be a good start and this a cheap upgrade overall.
The question is whether the cabling is transferable. Note that the radar can operate wireless/wifi. Note that your IPAD, Samsung and Smart Phones can also be connected to the new MFD, can control the displays and the autopilot P70r, can interface and be operated from all the devices (ray remote, free download)... so a ton of back up and flexibility. You also get the new CHIRP fish finer/depth finders, 3D....
If you don't go digital with new MFD, then you also miss out on AIS. Given the existing age, it is time to do the whole upgrade as if something fails... well you will likely face another upgrade... and the cheaper solution now , will not be in the long run... You will find support problems for the C80 in the near term... Analog s really over now..
Regards,
Viper