Hello, if i want to play Change of Plans what is the Deploy cost for Driven by Hatred Vader? 13 or 18?

FAQ:

Q: Does an "Attachment" Skirmish Upgrade card change the
deployment cost of the Deployment card to which it is attached?

A: No. The attachment is simply scored simultaneously when the
group to which it is attached is defeated. Any effects that refer
to a group's deployment cost do not take the cost of an attached
Skirmish Upgrade into account.