Currently wrapping up chapter 6, and since this is the last time I've access to Athkatla, are these items worth it for the rest of game? Sling of Everard, Vhailor's Helm, Helm of Brilliance, and the level 9 scrolls at Adventure Mart. I've 42k gold with 20 reputation so the costs range from 5838 (Helm of Brilliance) to 15750 (Sling of Everard).
Sling of Everard is probably a luxury but Aerie is a sling user and Jaheira rotates between tank and summoner. Also, I've read that there are a few enemies immune to weapons of +3 and lower.
Helm of Brilliance is nice to have but are liches and other undead still a threat in chapter 7 and Throne of Bhaal? A second casting of Sunray would be awfully nice to pair with Daystar.
I think Black Blade, Chain Contingency, Shapechange, and Time Stop would be fun to cheese through Project Image/Simalcrum but I've no idea how common those scrolls are dropped in chapter 7 and beyond.
My team consists of pc berserker (9)->mage dual wielding longswords, Jaheira, Minsc, Keldorn, Aerie, and Imoen.