Both can vary widely, but I think you are in the ballpark.
Although I would consider anything electric
over 5 yrs old to be worthless from a valuation standpoint.
Both are an easy install, complicated part is the thru-hull.
Actually I think I spent closer to $3K for my AC
And you can go as little as $2K or less for Radar, or much higher if you chose
Biggest savings is if you do the install
I link to Defender as they are easy, but shop around, give Hopcar a chance, he usually comes up with better prices