AT&T is planning to put some extra shine on the even sleeker new Apple iPhone. When the 3G iPhone is introduced this summer, AT&T, the exclusive U.S. iPhone sales partner with Apple, will cut the price by as much as $200, according to a person familiar with the strategy. AT&T is preparing to subsidize $200 of the cost of a new iPhone, bringing the price down to $199 for customers who sign two-year contracts, the source says. Apple is expected to have two versions of the new iPhone, an 8-gigabyte-memory and a 16-gigabyte-memory model with price tags widely expected to be $399 and $499. AT&T and Apple declined to comment.