The KR could have sold for more at auction or on BaT. I think Jeff's evaluation was fair, considering the cost to restore it and purchase the missing parts (starter delay and carb are $$ items). Figure an easy $100k+ would have to be spent for restoration and then it's getting into the area of concours values.
Both of the cars being in Maryland probably had a lot of hidden rust issues and who knows what else (how bad was the LH hit on the KR?). There are most likely pitted suspension/steering parts and lots of trim that will need to be replaced. Evaluating 50+ year old cars is not the same as a 5 year old Camry, it's not easy to give an accurate assessment, especially on a car all put together.
It appears the buyer and seller found an agreeable middle ground that was fair to each and at the end of the day, that's all that matters.