FB , Tan Kin Lian  4 Nov 2025,
Based on the context available:
 * Lee Hsien Loong sold the house to his brother at market value on the condition that both brothers would donate an amount equivalent to half the value of the house to charity.
 * Lee Hsien Loong later revealed that he had donated 100% of his own proceeds from the sale to charity, which would be an amount equal to the full market value. Additionally, one snippet states he "donated a further equivalent sum," suggesting a total donation of twice the half-value he was required to donate, but the Wikipedia snippet clarifies he "donated 100% of his own proceeds," which is the full market value.
 * Lee Hsien Yang was conditionally required to donate an amount equivalent to half the value of the house to charity. In a statement, he rejected the suggestion that he was seeking financial profit from redevelopment and said the price he paid was "simply a price I paid to help ensure my father's wishes are honoured."
 * A joint statement issued by the three siblings in December 2015 said that Lee Hsien Loong and Lee Hsien Yang "have each agreed to donate half the value of Mr Lee Kuan Yew's Oxley Road house to eight charities."
The specific dollar amount of the donation is not available in the context, as the exact market value of the house at the time of the sale in late 2015 is not specified, though one source notes "conservative estimates in 2015 put the value of the plot at $24 million."