Qqueer as a three-dollar bill means very strange.
Also,American idiomatic expression describing someone as obviously or positively homosexual
Today I saw a woman pushing a lawn mower down the street and singing to it as she went. I thought she was queer as a three-dollar bill.
JILL: In all the years I've known him, Mike has never had a suit and he goes barefoot.
FRED: That's because he's as queer as a three-dollar bill