The use of technology in business in the era of 4.0 is a difficult task for Small and Medium Enterprises (SMEs) due to lack of resources and other market problems. To attract customers to buy a product, the marketing of a product is usually influenced by various factors, such as price, product quality, and brand. In this study, the researchers analyzed the impact of price, product quality, and product brand on customer’s buying interest. This research is a case study conducted in Fahmi Mandiri SMEs aiming to increase the income. The method used is multiple regression analysis and the data is collected through questionnaires distributed to the customers. The results show that the biggest partial correlation influencing customer buying interest are price of a product and product brand. The quality of a product does not affect customers' buying interest significantly, because consumers will trust the quality of a product when the product brand is known and has the right price.