What does the cryptic crossword clue "Central economic unit some say is indispensable (2,3)" mean?

The wordplay uses a charade (building blocks). NO (synonym="NO") + ONE (synonym="unit") = NOONE The answer is NOONE.

Central economic unit some say is indispensable (2,3)

Guardian Cryptic #29644 | 19 Across | 2025-03-17 flower