I'd like to bring up the lack of middle ground for DC30 alchemical reagents.
DC 30 reagents represent an important "stepping stone" in the progression of alchemists since DC35 ingredients are not only (justifiably) rare and low in quantity, they tend to be too hard for medium-level alchemists to achieve. In my experience, your alchemy progression tends to slow to a crawl after you've hit the ~25 level because of the lack of DC30 reagent options.
There's only really two place to reliably get DC30 reagents in any kind of quantity; one of them is, you guessed it, the Alhoon, and the other is Perfidus (the ice demon hearts at moderate spawns).
The problem is that the Alhoon is for a party of level 10s and Perfidus is a great challenge even for a party of 17+'s the minute Pit Fiends start to show up. One's too easy and the other's too hard.There's little middle ground.
Sure, there's also a handful of bone golems in the Terg Crypts or the Skeleton Lord caves, but those are relatively few in quantity and they're also edging on being too low CR for the kind of parties that most middle-level alchemists are.
I'd like to recommend that more DC30 reagents be added -- especially in Hazlan or any dungeons aimed at the ~13-16 party range. This would give the enterprising alchemist a chance to find a good quantity of reagents while avoiding dungeons that are too weak for him.