Studies not done by those with a vested interest in "piracy" being a rampant problem (RIAA, MPAA, Etc) show that the largest reason for piracy isn't because it's free. It's a service problem. Time and time again, it's been shown that you can "solve" piracy by offering a service that is accessible, quality and priced appropriately. Netflix and streaming services did more to reduce piracy than any law Enforcement action or expansion of copyright ever did. Of course, now with the segmentation and degradation of content across those services.. they're starting the cycle over.
On top of it, any number about how much is 'lost' on 'piracy' is completely made up. I can't speak to the NFL's number, but the MPAA for example includes the people working at coffee shops near where a movie is being shot as part of the 'lost money'.