Prosocial spending has been linked to positive benefits for individuals and societies. However, little is known about the precursors of prosocial spending directed to vulnerable people. We experimentally tested the effect of a first exposure to a prosocial donation decision on subsequent prosocial spending. We also examined the direct links from eudaimonic well-being beliefs (contribution-to-others and self-development) to prosocial spending, as well as the interaction between these beliefs and autonomy in predicting the money given. A total of 200 individuals participated in the study. Results showed that, compared to two control groups ("totally self-focused" and "no first-exposure"), an initial exposure to a prosocial donation decision increases subsequent prosocial spending. In addition, we observed an anchoring bias from the initial prosocial donation to subsequent prosocial spending. Regression analyses also confirmed the existence of a positive significant relationship between contribution-to-others beliefs and prosocial spending. Finally, we observed a significant interaction between autonomy and self-development well-being beliefs, such that autonomy strengthens the link from self-development beliefs to prosocial spending. In general, our results confirmed the significant role of exposure, anchoring, autonomy, and well-being beliefs in predicting the money spent to help vulnerable people.