Custom Post Type Meta Boxes

Change advanced to normal, this will at least move it up above some others.

However, there’s no guarantee you get the top spot, because a user can still drag and drop metaboxes around, or a core metabox or one added by another plugin might believe it is more important than yours.

There’s no way for WordPress could offer the top spot as an option, as what would happen when two plugins decided they both wanted it?

p.s. here’s how to move Yoast’s SEO plugin metabox down:

add_filter( 'wpseo_metabox_prio', 'move_yoast_metabox_down' );

function move_yoast_metabox_down( $priority ) {
    return 'low';
}