custom booking price placeholder

add_filter('em_booking_output_placeholder','my_em_custom_booking_price',1,3);
function my_em_custom_booking_price($replace, $EM_Booking, $result){
    switch( $result ){
        case '#_CUSTOMBOOKINGPRICE':
            $replace = $EM_Booking->get_price(false);
            break;
    }
    return $replace;
}