SANTA MONICA, Calif., Feb. 23, 2000 -- "Scream 3" and "Titus" haven't hit the shelves of video stores yet, but if you stop off at the market on your way home today, you might be able to buy them. But bring your inheritance, because they'll probably cost you six figures. The horror hit and the Shakespearean tragedy are just two of the roughly 350 movies that are up for grabs (that is, if you happen to be an overseas film distributor) at the market -- the American Film Market, that is -- the annual international trade show for the motion picture industry, running here today through March 1. Founded in 1981, the AFM is now the largest movie market in the world, and organizers say about $400 million in licensing deals will be inked in the coming week. The AFM isn't a film festival -- there are no awards, and don't expect to see Sundance stalwarts such as Ben Affleck and Steve