ET Jaynes' Probability Theory treats this a bit - some hypotheses will strictly dominate others, it's true.

However, I don't think it's so simple to say that your specific example is unbelievable. I would bet I could find a way to give you evidence of your sanity that is independent of whether psychics exist. The probability that you're being tricked can be reduced by writing the code and conducting the experiments yourself. Therefore the posterior probabilities don't all move as one, so under some situations you could believe that psychic powers are real.