What principle dictates that a buyer will not pay more than the cost of an equally desirable substitute property?

The principle that states a buyer will not pay more than the cost of an equally desirable substitute property is the Principle of Substitution. This principle is foundational in real estate valuation and economic theory, focusing on the idea that in a competitive market, there is an upper limit to how much a buyer is willing to pay for a property based on the costs associated with purchasing an equivalent alternative.

If a comparable property offers the same benefits and features, a buyer will typically choose the one priced lower, thus ensuring that any seller pricing their property significantly above this level may struggle to find a buyer. This concept helps to establish market value, as it reflects the relationship between supply and demand for similar properties, pushing the value toward a level that is consistent with alternatives available in the market.

The other principles mentioned play essential roles in real estate economics but serve different purposes. The Principle of Value relates to various factors influencing worth, the Principle of Competition looks at how competing properties can influence pricing dynamics, and the Principle of Supply and Demand addresses broader market trends rather than the specific decision-making behavior encapsulated by substitution.