No idea. They'll be copies from original prints or negatives and, depending on the subject, will be valued at the price of the paper they are printed on, or what an individual is prepared to pay, for example on that well known Internet auction site.
If you're considering selling them, then it will be useful to try to establish some background on the person who originally had them in their care - perhaps at one time an aviation journalist, for example - and whether he 'owned ' them legally. Also, identification of each subject shown would help. Perhaps also check the legality by contacting the original source, at the address on the prints - they may be under tight copyright still (probably are) are perhaps even still 'owned' by the present company or estate.