Consumers are widely assumed to buy the cheapest produce, but the price assessment mechanism in produce purchasing is unclear. The concept of reference price (both internal and external reference prices) reveals the mechanisms by which consumers determine their sensitivity toward a product's price. Although most studies have focused mainly on industrial products and processed food, few studies have investigated the case of produce. Therefore, this study elucidates how consumers recognize prices and use a reference price to determine the produce to be purchased. The study process involved experiments in simulated store as well as interviews and questionnaires. The results verified the model of the price determination process using reference prices in produce purchases. No participants referenced only the price. Most consumers who evaluate prices and quality compare the reference price and selling price during purchase, determine if the produce is undervalued or overvalued, and only then make a purchasing decision. After a purchase, the consumer's internal reference price is either updated or remains the same. Many participants used an internal reference price formed by prior purchasing experiences (previously seen price). This study therefore reveals the mechanism of price judgment and internal reference price in produce purchases. Consumers compare their internal reference price with the actual selling price and tend to avoid higher (internal reference price > selling price) than lower (internal reference price < selling price) prices. In addition, the findings suggest that as retailers set a cheaper price, consumers seek an even lower price because their internal reference price is revised downward due to this cheaper selling price.