સોનું જાણી સંધર્યું. નીકળ્યું કથીર.

sōnuṁ jāṇī saṁdharyuṁ. nīkaḷyuṁ kathīra.

Literally: Stored away thinking it was gold; it turned out to be pewter.
What it means: Expecting great value from something that turns out to be completely worthless.

Also said as

ગુજરાતી કહેવતસંગ્રહ (Gujarati Kahevat Sangrah) (1921) · 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.