Q. Is it correct to say $3–5 million? Or should it be $3 to $5 million? Or $3 million to $5 million?

A. These are all acceptable ways to express the same thing. With regard to the $ symbol with inclusive numbers, in Chicago style an abbreviation or symbol is repeated if it is closed up to a number but not if it is separated by a space: $3–$5 million, but 2 × 5 in. (See CMOS 9.17.)