Albert Barnes Commentary Proverbs 14:24

"The crown of the wise is their riches; [But] the folly of fools is [only] folly." — Proverbs 14:24 (ASV)

The crown, that is, the glory of the wise man constitutes his wealth. He alone is truly rich even as he alone (compare Proverbs 14:18 note) is truly king.

The seeming tautology of the second clause is really its point. Turn the foolishness of fools as you will, it comes back to foolishness at last.