[Jack Simth]

Yeah - pick up a few scrolls (spell level * caster level * 25 + Material Components Cost + 5*XP cost) of a few spells, and scribe them into your Blessed Book - a 7th level spell scroll, with no XP or expensive Material Components, costs 2275 gp (7th level spell, caster level 13th); 6th costs 1650, 5th costs 1125, 4th costs 700, 3rd 375, 2nd 150, 1st 25.

Also consider a safe rest spells (such as Rope Trick (2nd), Secure Shelter (4th), or Mage's Magnificient Mansion (7th)), some buffing spells (Mass Bear's Endurance would grant every living critter in the party quite a few extra HP for a time, while Mass Cat's Grace increases AC (by raising Dex) and Mass Bull's Strength increases damage; even the lowly Mage Armor can really help those that, for one reason or another, aren't wearing significant amounts of armor), and utility spells (okay ... what do you do if, say, an Invisible Stalker decides you would make an excellent target? Likewise, sure, you can use Overland Flight to stay out of ground-based combat and get over those peksy walls, but that isn't going to let anyone else in the party follow you; et cetera)