A bar close to one of our question setters has started running quiz nights, and we had heard that the number of points that you get for a correct answer depends on how hard the quizmaster thinks the question is. We all had a few reservations about this.
She eventually went along, and unfortunately these reservations were well founded.
Difficulty is quite subjective and the difficulties assigned to the questions in the quiz were very random. Our question setter was the only person there who knew the answer to one question, and gained three points. Then a very easy question that virtually everyone knew got 20 points.
In addition, a handful of quite high-value questions had incorrect answers, which made matters even worse.
I'm afraid we can't recommend this approach.