NEW YORK - Rapper 50 Cent's euphoria of owning a grand 21-bedroom mansion soon gave way to a headache over the cost of maintaining the property.

He had to spend almost US$70,000 (S$94,900) a month to upkeep the property - on 50,000 sq ft of land in Farmington, Connecticut - which he bought for US$4.1 million in 2003.

"You know when you look down the hallway in your house and you don't wanna go down there?

"Things would break because you didn't use them (regularly).

"You didn't turn it on, now the light is flickering," he once complained to talk show host Stephen Colbert.

The 43-year-old musician put the house on the market for US$18.5 million in 2007, but despite making price cuts over the years, managed to find a buyer only recently, reported the Rap-up portal.

The rapper is donating the entire US$2.9 million proceeds to his G-Unity Foundation, which supports organisations that work to boost the quality of life for low-income and under-served communities.