To gain the reduce price, the feat must be involved in the creation process; ergo you are crafting an item "with the feat" in much the same manner as you would say, craft a sword "with the anvil"; it may not be the hammer, the steel or the fire, but it is directly involved in the creation process.
Here's one. Region of Dream flowing time trait prevents the gain or loss of exp while affected by it, Manifest zone, psionic allows you to link a manifest field.
Related to that, a Stronghold space with the spell "Dream Travel" feature instead of teleport, would net you an extra 14.75 hours a day in work time. (or more with uses per day) [Note Dream Travel has a little note at the end that nullifies the consumable restriction of the time trait.)
(which is close to a 62% reduction in objective time)
Related planar stupidity
Take a squirrel, give it a little pouch with something valuable and or rare. Make sure it's unconscious.
Get naked (this is important)
Send the Squirrel into the mirror using Mirror Walking
Enter the Mirror realm (still naked)
Have your assistant enter with the items you need (a cage and your gear with preferably with some sort of fast equip or a summons spell)
He gives them to you, then returns.
At this point, in your mirror realm there are 2 Squirrels, 2 Pouches, 1 naked you, and 1 equipped you (as the mirror friends stuff vanished when he left.)
Steal the original squirrels pouch
Murder your naked self.
Place the put the doppel squirrel in with the original and fix whatever condition renders the doppel unconscious.
Let nature take its course.
Leave with both pouches 1 dead squirrel and 1 mirror squirrel.
Petrify or stasis the squirrel when you get back.
Yes this cost you roughly 3 ea. lvl 5 spell slots, but it lets you copy any object, including artifacts at level 9 so it's probably worth it.
You should now have 2x whatever you needed copied, as long as no one kills the Squirrel or Breaks the Statue.
You could also glue a Box to a turtle, why not.