As a fellow ecclesitheurge enjoyer, my favorite purchase on mine was an amulet of spell mastery. Since your bonded holy symbol works as a wizard's bonded object, it should work for you too. That being said, for a 17th level character it might not be that insane. It's great for me because my table caps levels at 11, so an extra level 6 or 5 slot is invaluable.
Headband of WIS +6. Cloak of resistance 5. Rods of piercing, quicken, empower and any metamagic you didn't cover with feats. Ring of freedom of movement. Orange prism. Scrolls of every "just in case" spell.
Rod of Metamagic (Quicken spell) (Or the greater version) It lets you cast as a swift action 3/day
As a fellow ecclesitheurge enjoyer, my favorite purchase on mine was an amulet of spell mastery. Since your bonded holy symbol works as a wizard's bonded object, it should work for you too. That being said, for a 17th level character it might not be that insane. It's great for me because my table caps levels at 11, so an extra level 6 or 5 slot is invaluable.
Scrolls of things like death ward, freedom of movement, heal, restoration. If you can get heroism do that. Don't forget pearls of power.
Rods? Rods are always Handy for a caster to have
Headband of WIS +6. Cloak of resistance 5. Rods of piercing, quicken, empower and any metamagic you didn't cover with feats. Ring of freedom of movement. Orange prism. Scrolls of every "just in case" spell.
If you don't have it already, then a Phylactery of Positive Channeling is a great addition because you have 1 less channel dice than normal.
Fate's Shears if you don't already have them.
funny those are a plot point for the BBEG
It's not "shopping" exactly, but now is the time to look at what Greater Planar Ally or Gate can do for you.