Why is PEEK filament so expensive? High performance polymers are becoming available for specific applications.

One of such materials is PEEK (PolyEther Ether Ketone), a thermoplastic polymer in the polyaryletherketone (PAEK) family. PEEK competes with certain Aluminium alloys but is half the weight of Aluminium. For aerospace application this sounds very promising!

NASA has shown that printing these types of polymers is feasible using low-cost, open source hardware.

Does anybody know why the prices of PEEK are so high?

Depending on the supplier/manufacturer you're looking at about 700 - 900 Euro per kg.
My assumptions about PEEK filament price are:


Raw material is more expensive. Compare price of ABS with PEEK pellets.
Demand is much lower. There are not many printers able to print peek. If you manufacture PEEK filament you have to store a filament batch for longer time. Manufacturer has to calculate into price storage space, material degradation, ...
Filament machine tuning. You have to tune filament extrude machine for PEEK, which takes time because it's a totally different plastic. Maybe there is a cleanup needed after finishing a batch and switching to another material.
Working conditions. PEEK is quite smelly and I am not sure if you have to improve work conditions like better ventilation. 
Research costs. You have to distribute research costs to a filament production where demand is low.