I've seen that deal being described as "far from lucrative" in a few articles now without managing to find an actual figure.
Yeah I just had a quick google and didn't find any numbers, people are saying on forums however that the NBL still pays Fox, of course you have to take that for what it is.
What I have read is that the deal is for five years but Fox gets to terminate it at the end of this year if the ratings and fan engagement isn't there. It's also conditional of the NBL setting up a team in Brisbane. Regardless of whether its forty million or if the NBL is paying for it to be broadcast the original point was that Fox would up the money for the A-League just because they spend so much money on other sports which is obviuosly flawed. Even if they are not now, in the past the NBL had to pay to be on TV.