What is the best way to write "invoicing $1 - 2 million, monthly"? Like that? With another dollar sign in front of the 2? Some other way???
Suzi, it's fine the way it is, as long as you take out the spaces on either side of the hyphen.
(Technically, it's supposed to be "$1 million-2 million," because without inserting the first "million" it really means "one dollar to two million dollars." However, that's not how people read it -- the read it as meaning "one million to two million" -- and I've seen even the NY Times use the "$1-2 million" construction.)
(So, to sum up, it's fine, just take out the spaces around the hyphen.)