Balancing an "Artificer" feat

[comrade raoul]

I'm trying to design a feat for characters who specialize in item creation. Here's what it looks like, though I've got a question.

Artificer [General]
You're very good at creating magical items quickly and efficiently.
Prerequisite: Any three item creation feats, two Craft skills with 12 ranks in each.
Benefit: You create magical items in half the normal time, and your gold and experience costs for creating the item are reduced by n%.

So the question is -- what should n be? 10%? 15%? 20% 25%? If n is 10% or 15%, would it be balanced to include an "Improved Artificer" feat that reduced costs by 25%?

 

[las]

I would say the 10% for this one then make a better one with 20% would do nicely.

 

[Spatzimaus]

The FR Feat "Magical Artisan" reduces cost (including gold, XP, and time) by 25% for one specific item creation Feat. Your Feat works for all types of items, so I'd say that even n=0 (that is, it reduces time by half but nothing else) would STILL be overpowered.

 

[Sollir Furryfoot]

I would say, 15% off to all item creation feats, since this not only lowers the price but the creation time. Note that it stacks with the magical artisan feat and I think its a fair trade off (although it may or may not still be unbalanced, either way that's 5 feats -none of which can be starting feats- to get 40% off of something).