I bought a rebuilt 1950 216 today for under $1 a cubic inch!
The seller is a very cool car guy who I met through a friend's uncle. He bought a 1949 1-ton Chevy a few years ago that came with this spare 216 that had been rebuilt by the previous owner but never used.
Apparently the p/o thought the original 216 was on its last legs, but its still running 10+ years later. The rebuilt spare has been sitting in a heated garage on an engine stand just taking up space.
It even came with a spec sheet of the rebuild. It looks like about $800 was put into it at the time. One quirk, it's a 216 with a 235 head.
Here are some pics of the new 216. I'm going to pull the valve cover and pan off to make sure things are looking ok, paint it and swap over some better parts from my seized 1951 and then drop it in!