What is the cost to add additional abilities to a Staff using Craft Wondrous Items?

[harmor]

I don't mean spells I mean abilities like a +4 enhancement bonus to Intelligence using Craft Wondrous Items? Is it just 150% of the normal cost or is it 300% because its unslotted?

Example item: Staff of Power

[Sigurd]

Unslotted, if you can do it at all.

Headband +4 int is 36k so 108k would be the ballpark. The danger of course is it could stack with more common int items. If you specified in the creation that it couldn't stack you might drop the price.

[John Spalding]

I think it is only double for being slotless.

PFSRD wrote:

No space limitation. Multiply entire cost by 2 and

An item that does not take up one of the spaces on a body costs double.