Which concept holds that consumers will favor the products that are easily available at an affordable price?

The concept you are referring to is known as "Convenience Pricing" or more broadly, the idea of "Accessibility." This concept suggests that consumers are more likely to choose products that are readily available and priced affordably.

Convenience plays a crucial role in consumer behavior, as it reflects the ease with which a customer can access a product. If a product is easily available in stores or online and does not strain the consumer's budget, it increases the likelihood of purchase. This principle is often applied in marketing strategies and pricing tactics to enhance sales and customer satisfaction, as consumers generally prefer options that require minimal effort and fit within their financial means.