Comparing Radar to AIS is not really very valid. You did not describe the type and location of sailing you plan on.
Fair point, sorry.
I sail San Francisco bay and the surrounding coastal areas. I am a desk jockey during the work week, so I only occasionally cruise. I am looking at making some longer trips this year, to places such as Catalina Island (~450nm) when I can get some vacation and am thinking about changes I need to make to the boat.
It looks like I can get an AIS send/receive along with a little plotter display from for about $1300, and be able to install it myself. RADAR is more like $3000+ for an entry unit, and uses significantly more power as was pointed out. (right now the boat uses almost no energy, and it would be nice to keep it that way)
So, RADAR users out there: Do you leave it on all the time? Or just for the occasional check?