Marketing managers decide on sales prices and consumers decide on their expenses. Knowing consumer behavior is concerned not only with marketing but also with behavioral economics that uses the theory of mental accounting. In the context of the philosophy of behavioral economics, the mental accounting theory belongs to the part of distributing consumers to rationally thinking and decisive consumer and into intuitive consumers. The theory of mental accounting suggests that individuals are likely to assign different functions to each asset group and in this case, the result of which can be an irrational and detrimental set of behaviors. We compare marketing and mental accounting approaches to investigating consumer decision-making about consumer spending on consumer baskets, but also on making decisions about purchasing long-term products and services.