Gayer than a $2 dollar bill or 3 dollar bill

The expression is "queer as a $3 bill", where queer has a double meaning. The original meaning of queer was "strange or odd". A $3 bill would be strange, since they aren't printed - at least they aren't in the US.

The two-dollar bill may not be queer anymore, but it’s still odd. And it’s still out there somewhere. A lot of them, actually. In , the U.S. Treasury reported $ billion worth of $2 bills in circulation. That sounds a lot, but we’re talking about percent of the $2 trillion in circulation at the time.