Wizards may start with any legal spells memorized. That is, they need not own a spellbook containing those spells. However, they may wish to take along one or more spellbooks in case a fight lasts more than one day and they need to rememorize spells. In that case, the wizard must pay normally for additional spellbooks and spells beyond those granted by the class.
Also, the following clarifications from last year apply this year too: