How is this legal?

Apparently the Martha's Vineyard home favored by the Obamas for their vacations, and owned by an Obama backer, is on the market for nearly $18 million.  Now if we calculate that rent on such a property would be somewhere between 0.1% of value/day ($18,000) to 1% of value/month ($180k/month), how, exactly, can we assume the Obamas could have afforded the $45k-126k/week rent on this place?  At 7000 square feet, it's not as if the Secret Service would have been paying for most of the rent, after all, because the President and his family would have been using a great portion of the home.  The article also mentions that a getaway favored by the Clintons sold for $29 million recently.


Seems to me that the vacation homes used by Democratic Presidents seem to heavily subsidize the left, which suggests to me that these "brother in law" prices are in effect...bribes.  If it's not illegal, it should be.