Ж85
ЖУРАВЛЬ В НЁБЕ
collNPsing onlyfixed WO sth. desirable yet extremely difficult to obtain, achieve etc: (like) the proverbial two birds in the bush.
From the proverb «Лучше синица в руках, чем журавль в небе» (аА bird in the hand is worth two in the bush"). See C-195.