One of the greatest examples of greed during the "Gilded Age" was the enormous amounts of money the railroad companies managed to accumulate. The owners of the railroads lived in opulence, surrounded by luxury and excess, while the workers lived in poverty. Exorbitant amounts of money were spent maintaining the lifestyles of the privileged few. These railroads also grabbed up land from everybody they came in contact with and often used forceful means to take it.
During President Grant's administration, dishonest scalawags and carpetbaggers roamed the countryside. They claimed to want to help the South during Reconstruction, but most of them were taking advantage of people for their own gain and prosperity. William M. (Boss) Tweed ran a mob organization that used illegal means to get monetary gain. These are just two examples of greed during the Gilded Age.
The wealthy class's lavish houses were made of the most expensive materials like marble and gold. The wealthy class lived in the suburbs and took vacations. Andrew Carnegie is one of the people that defines the gilded age. For more information check out an AP US History textbook. That's how I learned it.