Dug up the rest of the specific cost reducers:
Templates (DMGII): explicitly do not reduce component costs.
Portal Master: 50% "normal cost" but does not stack with magical artisan.
The Caster Shield is only for raw materials and is another instance where that term is differentiated from material components.
Blood Artisan: 75% "normal cost" for Magic Arms and Armor as well as Wondrous Items, but all items you create have a randomly determined curse.
Fey Cherry wood's phrasing was somewhat ambiguous:
... items made from fey cherry wood cost 10% less gp and XP to enhance magically.
(Also Bastian, you have the Dragon Mag number as 257 in your guide.)
Unbound Scroll has almost identical phrasing, followed by mentioning that this discount stacks with that of Extraordinary Artisan which does not discount material component costs.
Tangentially related would be that different item types require different amounts of material components for crafting. Wands and Staves of course require 50 times the amount it would cost to cast the pertinent spell once. Weapons, Rods, and Wondrous Items do not require material components at all for their crafting processes. Potions will only require enough for one casting. Armor and scrolls have me a bit hung up though: either they only need enough of the appropriate component for one casting, or they need enough components to cast the spell each day of crafting and I'm not sure which it is.
EDIT: Oh, and I get that it's there for thoroughness, but is it even possible to get Divine Rank as a PC? It has a similar "the cost" wording to fey cherry wood and unbound scroll but I somehow don't think it much matters...
EDIT: (mostly for my own use as I still pop back here every so often) At some point I figured out that crafting armor does not require material components for the pertinent spells, and crafting a scroll would require one copy of the appropriate component. Darned if I can remember what I pulled this conclusion from though.