વણ પ્રધાને વાણીઆ, ગયું રાવણનું રાજ. અથવા વણ વજીરે વાણીઆ, ગઈ રાવણની લંક.

vaṇa pradhānē vāṇīā, gayuṁ rāvaṇanuṁ rāja. athavā vaṇa vajīrē vāṇīā, gaī rāvaṇanī laṁka.

Literally: Without a minister, the merchants ruled, and Ravana's kingdom was lost. Or: Without a vizier, the merchants ruled, and Ravana's Lanka was lost.
What it means: A state or enterprise will fall to ruin if it is managed by greedy traders instead of wise statesmen.

Also said as

ગુજરાતી કહેવતસંગ્રહ (Gujarati Kahevat Sangrah) (1923) · read from the scan by machine — the Gujarati itself is unchecked · English is machine-made and nobody has checked it yet

Heard it differently, or know we've got the sense wrong? Tell us — that is exactly the kind of correction this needs.