Starwood tend to have their yearly Starpoints sale always around this time. You can buy/gift the maximum number of Starpoints 20K per calendar per account. This offer is valid between October 15 and November 30, 2012. You can access this offer here.
The price of 20K Starpoints is $560. The price of a point is 2.8 cents. You can transfers SPG points to many airlines and the price of a mile under this offer would 2.24 cents when the 5K transfer bonus is factored in.
You can buy the 20K points for your account and gift to as many accounts as you wish. Any one account cannot receive more than 20K bought Starpoints per year, whether they are gifted or bought by the account holder.
If you are short of Starpoints for a big award, this is about the lowest that you can buy them at. You can transfer 20K Starpoints to 25K airline miles on most of the Starwood’s airline partners.