I've been active duty AF for 25 yrs, and started flying in 1989. I was issued the orange knife and still have it...brand new. I never liked it, and thought the quality was lacking. Today, there are so many great production choices that are easily purchased depending on your AFSC, but a few us choose to carry our customs exclusively.
It was actually suppose to be carried in the flight suit knife pocket on the inside of the left leg. The nylon lanyard is still standard issue inside the flight suit.
I wouldn't give over $20 for one...but that's me. That said, I won't sell mine either. I carry my custom aircrew fixed blade there, instead of a fat folder.