”Ally McBeal” costar Portia de Rossi is saying bye-bye to the penthouse perch she bought just two years ago. Purchased for about $600,000, the three-story, 2,600-square-foot apartment stretches up to the top floor of the legendary Hollywood building where Marilyn Monroe and Rock Hudson once lived. The seven-story, French Normandy-style 1930 structure has a pool, a spa, a private garden, and a doorman. (Re/Max’s Brian and Laura Moore have the listing.) De Rossi is moving to another home in L.A.