Understanding human decision-making procedures commenced during the mid-20th-century cognitive revolution. The interplay between cognitive biases and heuristics in consumer behavior is investigated in the present study. We show that heuristics and biases significantly affect how people make decisions by using data from an online poll with five different groups of Chinese and Korean high school and college students and using differences in how much time they spent on different cognitive events. Our results confirm the theory that biases and heuristics can cause illogical decisions. The rise in irrational decisions is especially noticeable when scarcity strategies are mixed with loss aversion. Further investigation shows that the mix of cognitive biases and heuristics significantly influences purchasing decisions, producing more irrational conclusions than depending on heuristics. These findings provide a deeper understanding of consumer behavior and the role of cognitive biases, enlightening the academic and professional community in this field.