I hope the trade idea was a joke. We're talking about a photo of a crashed aircraft, and it sounds to me as if they're asking for it to directly assist in or support an investigation. (There's no other reason they'd need a "terrible" photo of an airplane taken from the window of another airplane - they could easily get a perfect photo of almost any aircraft if they just wanted to show what an aircraft looked like before a crash. There must be something they see in the photo.)
Give them the picture, no questions asked, no strings attached. If it's such a bad photo to begin with, I don't even see why you'd care what's done with it. Not every photo is worth defending to begin with, and if the NTSB is asking for it in relation to an investigation, I think you have a moral obligation to give it to them.
I'm tired of being a wanna-be league bowler. I wanna be a league bowler!