Mill & Bentham texts talk about Utilitarianism, which would indeed justify torture of one person for "the greatest utility for the greatest number of people". However, that is what Wilfsell has been advocating (see her posts below), and not me.
I have been talking about the Utility Function in economy, which involves the pleasure/pain each individual gets from each product/service personally. In simple terms, my utility function might be:
5food + 6books + 1holidays + 2nice clothes...
Someone else's might be:
3food + 1books + 7holidays + 5nice clothes...
So the whereas I will spend lots of money on food and books (to maximise my own utility function), this other person would fly away on a holiday at every chance.
My point was that we all have different Utility Functions and hence it is not possible to determine common needs for everyone and discard the rest as inessentials.