Redemption Grace Period or RGP.
When a domain name expires there is a certain period (usually 30 days) during which you can renew the domain name at the normal price.
After that follows the so called Redemption period when you can renew the domain name at a higher price due the taxes applied for holding your domain. Below follows the official information regarding the RGP period according ICANN.
During the Redemption Grace Period, registrants could redeem their registrations through registrars. Registrars would be able to redeem the name in the registry for the original registrant by paying renewal fees, plus a service charge, to the registry operator. Any party requesting redemption would be required to prove its identity as the original registrant of the name.
In order to renew the domain name now you have to pay additionally (a penalty fee due to the registry for restoring the domain name). If you wish to do so, please contact the Sales Department by opening a support ticket from your Web Hosting Control Panel.