I remember reading a book I checked out from my local library in the late 70's or early 80's, and I'm trying to find the name (and hopefully a copy I can read again). The novel featured three young people (or possibly two young people, guy and girl, and and older man), all of whom had some psychic powers, who get stranded on a somewhat backwater planet and are trying to leave. In one scene, I remember them attending a circus or traveling carnival, and being worried about tipping their hands about being able to read minds. And I remember in the climax, one of the characters sacrifices himself to enable the other two to get away (though he does climb into some kind of "auto doc" and it may have been vague about whether he would pull through in the end).
Does this sound familiar to anyone?