Efficient Item Creation( Epic Level Handbook, p. 53)
Select an item creation feat. You can create magic items using that feat much more quickly than normal.
Select an item creation feat. Creating a magic item using that feat requires one day per 10,000 gp of the item's market price, with a minimum of one day.
You can gain this feat multiple times. Its effects do not stack. Each time you take the feat, it applies to a different item creation feat.
Without this feat, creating a magic item requires one day for each 1,000 gp of the item's market price.