A: During the grace period set by domain registry (domain supplier), it is allowed to extend the domain ownership at a regular price. But if the due is over, the price will rise unexpectedly. Also, if you miss the domain renewal for a certain period of time(generally about 2weeks), the domain ownership will be automatically expunged, which means nobody can guarantee that you can have your prior domain back. For such benefit and possible harms, we strongly suggest you renew your domain ownership in advance.