Though they are all second hand and no hard documentation, there are several reports that NWBO is selling the treatment in the UK Specials program at a price that aligns with what he asserts.
The problem is that means nothing wrt what it can actually price at in a broad market.
The last official statement on price from NWBO that I am aware of is what you cited.
BTW, I do think that if approved they can get a higher price than the numbers you extrapolate. But we have no hard data here. It is all guesswork. And at the end of the day would be up to NICE.