Questions about Halloween event salvage.

[Cyclops]

I've been selling it for $10K plus at Wentworths.

What are the various costume pieces used for?

Are they ingredients for recipes?

Should I hold on to what I have as it might increase in value?

 

I took a couple of toons from 1-12 just trick or treating...influence, experience and loot all in one package.

[Flashtoo]

You can exchange them at the Halloween vendors - one of each will get you an additional costume slot (one per customer), a spider vanity pet, or temporary NPC costume powers like the ones you get from Trick-or-Treat. The vendors are Annah in Croatoa, Granny Beldam in Nerva, and Acantha in Imperial City; they're all witches. Annah is the easiest to reach, as she's just outside the wall near the train station without any mobs to get between you and her.