Principle 3: Buy Many Small Pleasures Instead of Few Big Ones
Adaptation is a little bit like death: we fear it, fight it, and sometimes forestall it, but in the end, we always lose. And like death, there may be benefits to accepting its inevitability. If we inevitably adapt to the greatest delights that money can buy, than it may be better to indulge in a variety of frequent, small pleasures—double lattes, uptown pedicures, and high thread-count socks— rather than pouring money into large purchases, such as sports cars, dream vacations, and front-row concert tickets. This is not to say that there's anything wrong with large purchases, but as long as money is limited by its failure to grow on trees, we may be better off devoting our finite financial resources to purchasing frequent doses of lovely things rather than infrequent doses of lovelier things. Indeed, across many different domains, happiness is more strongly associated with the frequency than the intensity of people's positive affective experiences
--From "If Money Doesn't Make You Happy Then You Probably Aren't Spending It Right," by Elizabeth Dunn (University of British Columbia), Daniel T. Gilbert (Harvard University), Timothy D. Wilson (University of Virginia), 2010.