Frequent small purchases provide more sustained happiness than infrequent large purchases because the mind adapts to large purchases, making them seem normal over time, while the variety of small purchases offers less opportunity for adaptation.
"spend frequently on Small Things rather than infrequently on large things the reality is our minds have an ability to adjust to even the best experiences money could buy and then all of a sudden that becomes normal however it was found that our mind is much less likely to adapt to a variety of small purchases instead of a big one"