Mind you, most people in the AF realize that the idea of the Marines having the second most expensive fighter in history, so that they can put half a dozen of them on their amphibs and do CAS, is plain silly. They just don't say so in public.
Its a revealing mindset if true. The -B is not that much more than the -A the USAF are getting. I assume avionic, EW and stealth is fundamentally the same, extra doors aside.
It almost implies the USAF view is that the USMC aren't worthy of having a decent aircraft. Feels like a sticky wicket.