The value of 3 (5)
I believe the answer is:
merit
'the value of' 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 merit that I've seen before include "Just deserts" , "of a high order?" , "Have a right" , "Good point or quality" , "Worth; deserve" .)