Idiomatic expression that means something considered as worthless because one cannot get it is :
AHard nut to crack
BSour grapes
CBlack sheep
DDark horse
AHard nut to crack
BSour grapes
CBlack sheep
DDark horse
Related Questions:
Complete the sentence given below using the appropriate phrase from a foreign language used as an English idiom.
He went on .........about the importance of a sense of duty