Since they use the FreeBSD userland, it seems appropriate for Apple to kick in a little cash to the FreeBSD Foundation. The remaining ~$150k is an utter bargain considering how important those pieces are to iOS and Mac OS X ...
Not to say that we wouldn't appreciate monetary donations too, but Apple doesn't "owe" us anything.
That's the beautiful thing about BSD-style licenses. Once the code is out there, nobody ever has to reinvent the wheel for legal reasons again - only technical.
I mean how doesn't Apple/Sony benefit from keeping FreeBSD incredibly healthy?
...let's be very grateful they didn't rewrite everything from scratch...