Renew it now. If (God forbid!) it comes time to leave you won't be able to get a new one.
Its very cheap insurance.
My passport expired, too, but I don’t have the money to get it renewed. The first one I got was $10, the second was $85 and renewals were $40. Last I checked, renewals were $120 and so were new ones. I have no clue what they are now.