[Problem] To provide useful information for various users engaging in real estate sales transactions. [Solution] Provided is an information processing device equipped with : an information extraction unit which extracts information about a second real estate property, or a second transaction, that is similar to a first real estate property or a first transaction dealing with the first real estate property, on the basis of feature quantities of real estate properties or feature quantities of transactions dealing with real estate properties; and a transaction result estimation unit which estimates, on the basis of the extracted information, transaction results of the first transaction, including a first price associated with the first real estate property.