I'm facing the same question. I got a couple hundred pounds of BX wire. Found I could pull the wire from about two feet sections, not much longer than that. Makes for a lot of work.
I'm sure the wire is worth more, if you pull the copper out. But is the labor worth the extra money? I'm not sure. A friend of mine who handles junk says not.
Call the wrecking yards around you. One offered me next to nothing, another wrecking yard offered me money for the BX. I'll take it in tomorrow, hope they actually pay out.