A tip: whenever someone is using the word “freedom” in a way that seems hypocritical, try substituting in “traditional privileges” (and for “free,” “traditionally privileged”). Often, the real meaning will snap into place.
A great example is the debate over “free speech,” where people are shocked to learn that conservatives use the term opportunistically in their own favor while not caring about the free speech rights of pro-Palestinian activists, communists, etc. Just pull the old switcheroo, designate it as “traditionally privileged speech,” and voilà — everything becomes clear!
An und für sich 
A corollary: in case it seems like this tip is primarily applicable to people like your local right-wing AM talk radio host, it’s just as applicable to people like John Stuart Mill, John C. Calhoun, Thomas Jefferson, John Locke, and other “classical liberal” stalwarts. Not only is the image of a pure non-hypocritical defense of “freedom” allegedly prior to the corrupted hypocritical defense of entrenched privilege a photocopy without an original, but as is generally the case with reactionary fall-from-Eden tropes, the persistence of the image is itself a defense of entrenched privilege too.
So “freedom isn’t free” means “traditional privileges aren’t traditionally privileged?”
I think we all knew already that the phrase had no meaning.
Yep.
“Freedom’s just another word for nothin’ left to lose,
And nothin’ ain’t worth nothin’ but it’s free.”