Perquisite

Something gained from a place or employment over and above the ordinary salary or fixed wages for services rendered; especially, a fee allowed by law to an officer for a specific service.

Things gotten by a man's own industry, or purchased with his own money, as opposed to things which come to him by descent.

a right reserved exclusively by a particular person or group (especially a hereditary or official right); "suffrage was the prerogative of white adult males"