It is clear to me that the topic of this thread is a continuing issue that needs regular discussion. Here's the original quote from Bentham in which he compares music and poetry to push-pin. He never says that they are objectively of equal value, he is saying that at certain times and circumstances push-pin can be more valuable. But of course the reverse is true even under this analysis - at other times and circumstances music and poetry can bring much more pleasure than push-pin - and it would be ridiculous to say that the activities are always interchangeable.
Epicurus never makes such an interchangeability claim either. Both of them are highlighting that pleasure and pain are personal and subjective, and not something that have objective basis in a particular activity. There are in fact no such things as objective "pleasure units" or "pain units" that are inherent in particular objects and that everyone experiences the same at all times.
This is important because while bread and water CAN give the greatest pleasure to those who are hungriest, Epicurus never claims that they ALWAYS produce the greatest pleasure, and it would be ridiculous to argue that eating bread produces exactly the same effect in every respect as eating steak.
But that's what is implied in arguing that all you really need to experience the best life is bread and water. There are different perspectives invoked, and if you ignore the context of those perspectives you easily go from the profound to the ridiculous. To hold that "bread and water" produce the greatest pleasure and imply "always" in saying so is as wrong as saying "steak dinners produce the greatest pleasure with the implication that that is "always" the case.