Absurd result of devaluation (9)
I believe the answer is:
priceless
'absurd' is the definition.
(I've seen this before)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for priceless that I've seen before include "unaffordable?" , "of inestimable worth" , "Killing" , "Of inestimable value" , "Beyond value" .)