Reason, Spending, Utilitarianism

Instrumental Reason does not only supply a Means to an End, it also helps choose between Means to the same End, e. g. purchasing something, rather than stealing it or manufacturing it oneself.  Sometimes, a choice between Means can appear to be a choice between Ends, e. g. between purchasing a car and purchasing diamonds.  But, actually, in those cases, it is usually a choice between Means, to one and the same End, often Pleasure, which Quantification can facilitate.  Now, Smith proposes that national Wealth, and occasionally a fair distribution of that Wealth, is the ultimate End of Economic behavior, including spending, to which Selfish behavior is the best means.  Thus, his system is not Egoism, but a special case of Utilitarianism, according to which the Egoist option is always the best..  However, while Bentham follows him in conceiving Egoist behavior as the best Means to the Utilitarian End, Mill diverges, suggesting that benefiting others can be a Means to that End.  For example, giving money to charity could lead to healthier, and, thus, more productive beneficiaries, while spending on diamonds might be hoarded by the supplier. Thus, he implicitly challenges any purported kinship of Marginal Utility to his concept of Utility, because the former is usually presented as Egoist in scope, e. g. the value of diamonds vs. the value of water to one and the same person, rather than vs. the value of some vital Good to someone else.  So, Utilitarianism incorporates a more fully developed concept of Reason than simple Egoism, thereby better befitting it to represent more of the dimensions of Reason that spending involves.