Why do economist measure the cost or money price of things when opportunity cost is what you actually are considering when you decide whether or not to purchase something?

Economists measure the monetary price of goods and services because it provides a clear and quantifiable metric for comparing alternatives in decision-making. While opportunity cost reflects the value of the next best alternative foregone, the money price helps individuals and businesses assess affordability and budget constraints. By understanding both the price and the opportunity cost, consumers can make informed choices that align with their preferences and financial situation. Ultimately, the combination of these concepts facilitates better economic decision-making.