@Goldfish Would a 1/day item of
Splinter Spell Resistance be too expensive for the Erinyes basic kit? Using a
Lesser Talisman or two would be another cheap way to give equip minions with useful effects. The
Greater versions would be cheaper over the long run since they aren't consumed on use, but we could churn out lesser ones pretty easily.
They're more expensive than scrolls, but you can equip three at a time to your neck slot and they activate on their own. The wearer doesn't need UMD or to use an action on it.
For the Erinyes Arrow Protection, Good Fortune, and Triskelion would be useful and low level enough that we could get students to do it. They'd fit in well fluff wise too - as student projects for people on the crafting track at the Scholarum.
Edit: for people other than Erinyes the pentacle talisman is the most valuable. We can't afford continuous PfE for everyone who works for us, and cheaper items require you to know that you're going to need the effect, which is a serious weakness. A lesser pentacle would cost 60 IM and provide some protection from surprise enthrallment.
It's not perfect since you need to make the second save it allows to get the PfE, and it only lasts 5 rounds after that. However, with a little planning that'd be enough room to get out a warning at least. It's certainly better protection from surprise enchanters than most other things in that price range.
edit2: autocorrupt