It was gas-filled presumably ultra low loss RF cable, but the thief cut it into small sections so that they could take it away. You might be right about the 50% number of they had somehow managed to steal it as a single intact spool. As-is, the station even said that they wouldn’t be able to use it even now that it’s been recovered because of fears of gas leaks.

I doubt they would attempt to sell it as is. They'd break out the copper portion and trade on that alone