I've been putting together a spreadsheet of the elements, and I came across this little tidbit in Wikipedia:
(Rhenium) is among the ten most expensive metals on Earth, at times exceeding US$ 11,000 per kilogram. About 35 kilograms of Rhenium are required in the construction of a commercial jet engine.$385,000 worth of Rhenium to build a single jet engine!?!? Well, that would go a long way towards explaining why the things are so bleeding expensive. I would think that this would make their scrap value much higher than it is.
From The Expert Network:
Analysis: Rhenium is a critical metal, one without which it would be impossible to produce modern military jet engines, the most efficient jet engines for civilian aircraft, and rocket engines for military use and space exploration.Sorry about the picture. I got tired of looking at poor quality, fuzzy, smeared black and whites, and settled for this diagram of a Kawasaki gas turbine.
This is because when it is used in concentrations of 2 to 6% to make superalloys those alloys can be used to make jet and rocket engine components to contain and direct the superheated exhaust of jet and rocket engines without melting or losing their strength.
The higher the temperature at which a jet or rocket engine operates the more efficient and powerful it is.