I think it is an absurd amount of money that could restore the entire RAF WW2 planeset back to flying condition!  
The key words are private investment,  people looking to make a return on an investment in the museum shop / cafe from the thousands of visitors per year.  Call me a cynic but I just hate the idea that some suit is going to be using The Few as a money making venture. 
I'm all for remembering what The Few achieved (I made an entire squadron based on them   

 )   But for me it is hearing those Spits, Hurricanes, lancs  (no mossies / beaufighter  

)  beating up the skies over Duxford on a sunny July afternoon.   That is History brought back to life  

  Not hanging from some ceiling in a fancy museum.