"Rapid" Magic Item Activation

[Samwise]

What would a reasonable cost be to activate a magic item faster?
That is, from a standard action to a move action, move to swift, swift to immediate, and immediate to free.

[ketaro]

Are you trying to create a cost where one does not exist? Cause I'm pretty sure you can set the activation action of custom wondrous items to anything you want.

[Samwise]

Yes I am.
I am thinking about putting together a magic item set, and considering using the set abilities, which are supposed to be 10-30% of the value of the items required, to enable using the activations "faster". Instead of 3-5 items, all requiring swift actions to use, allowing some items to be activated during the same round.
I am trying to decide if that is reasonable.

Of course with existing items there is the question of how much it would change the cost of the item to have limited use activations be faster than those listed for the item.
"Zero" does not seem to be a reasonable cost, otherwise all wondrous items would have free activations for everything.

[crazypunk86]

you should price them by items rarity. It's a very basic solution for pricing magic items based on an item’s rarity level. It totally depends upon the items. Common items in the price range of 50-100 gp. Rare items may be worth as much as 5,000 or more. Legendary items could be worth more than 50,000 gp.

I hope this could help you to figure the reasonable cost.