Dmitri has saved $30 per week to buy a preowned gaming console. He compares two different models: a Sintendo that is priced at $130 and a Nony system that is priced at $140. Dmitri decides to purchase the used Nony system for $140. Identify what role money plays in each of the following parts of the story. Hint: Select each role only once. Role of Money Medium of Exchange Unit of Account Store of Value Dmitri can easily determine that.