public function filter_course_price( $price, $course ) {
		$course = dozent_get_course( $course );

		if ( $course->is_closed() ) {
			$course_id = $course->get_id();

			$product_id = dozent_get_attached_product_id_by_course( $course_id );

			$price = edd_price( $product_id, false );
		}

		return $price;
	}