Whatever it is, I imagine it was well worth it for the primary sponsor, Red Bull. A lot of the tech was developed just for this jump, so it would be difficult to get a final price tag without including R&D costs (which are already tricky).
Yup, definitely worth it! Imagine almost 5 million people essentially watching an almost 3 hour long (very interesting and groundbreaking!) Red Bull commercial around the world.
I think if we did the math at base advertising/marketing rates - this project would still work out quite cheap for that kind of exposure!