Interesting to see a value placed on an aircraft like that. 

I know of a couple of B-17 sales in recent years bit have never seen a price given for them.

Considering a Spitfire or Mustang is $3-4 million, $15 million for an airworthy B-17 is to be expected.

It will be interesting to see how much use it gets under a single owner. Large aircraft have such high maintenance and crew requirements, they are almost always operated by a group.

I wish the new owner luck.