It's generally easier to call for a price quote on a warranty extension.  That said, expect between $300-400 for a year's extension -- you might just be better off putting those funds aside for a repair in case it is needed.  
I am trying to renew my service contract which is about to expire in 10 days but when I fill the form and submit it says sorry it can be processed. Would like to know how I can renew the contract?
Renew Service Contract