This study aims to investigate the factors influencing donation intention when the option to donate is presented during a purchase decision. Through an experimental design, we examined how price differences and reference group effects impact donation intention. We created stimuli with three price difference conditions (high, low, and control) and two levels of referent power (high and low), and involved 480 Korean consumer panels in the experiments. After controlling for psychological reactance levels, a two-way MANCOVA confirmed the main effects of price difference and referent power but found no interaction effect between these variables. Notably, consumers were less likely to feel guilty for not selecting the donation option when its price was slightly higher than that of the non-donation option, compared to the scenario where the prices were the same. Additionally, consumers exposed to high referent power experienced greater irritation, guilt, and shame if they did not choose the donation option compared to the low referent power group. Multiple regression results showed that guilt significantly influenced the intention to purchase a donation option, whereas irritation and shame did not. These findings suggest that understanding situational factors such as price differences and referent power can help develop effective marketing strategies and encourage voluntary participation in donations.