leave (something) on the table v. phr. to refrain from taking the utmost advantage of something; to not address every aspect of a situation; in the form leave money on the table, to negotiate a deal that is less financially beneficial than is expected or possible. (source: Double-Tongued Dictionary)
Further reading
While reading Great Expectations (Bookshop|Amazon) by Charles Dickens, a listener in Arlington, Texas, is surprised when one of the characters inherits some money, which Dickens describes as a cool four thousand. Were they really using cool that way...
Among the proverbs in Leo Rosten’s Treasury of Jewish Quotations (Amazon): If you drop gold and books, pick up the books first, then the gold. This is part of a complete episode. Transcript of “Who Is Just Carrying Around Gold, Anyway?” Here’s a...