For 1000 Golden Eagles you can purchase a Premium account for a week, allowing you to earn two times more RP as well as more Silver Lions for each battle, or one of the premium machines.
For 2500 Golden Eagles you can purchase a Premium account for a month, allowing you to earn two times more RP as well as more Silver Lions for each battle, or one of the premium vehicles.
For 5000 Golden Eagles you can purchase a Premium account for three months, allowing you to earn two times more RP as well as more Silver Lions for each battle, or several top rank premium machines.