cash and xp for vanquishing

The cash you get equals the xp you earned when you vanquish an area so do scrolls and air of superiority increase this final amount of gold given?

Ive a few scrolls in storage but would it be worthwhile actually buying scrolls to increase the cash reward.

No, scrolls only raise the xp gained by killing foes. Quest and vanquish rewards are not affected by scrolls.

The cash/xp you get for vanquishing an area is a reward, just like you get for completing a quest/mission. You can't change the amount given to you.

Actually, you win gold and experience equal to five times the number of enemies you've slain. This is still a reward, so I don't believe experience scrolls work.

I believe the amount of Xp/Gold you get is directly related to the amount of monsters you kill in the area .. So if you get all the popup's you will propably get a little bit more xp and Gold.

Check:
http://gw.gamewikis.org/wiki/Vanquish

EDIT: Can also see on the wiki page that certain quests up/down the amount of monsters in the area. So if you want more xp/gold maybe ensure that you have the quest active when entering the area.

I've completed a 3,000 exp quest while vanquishing, and no, I didnt get that amount in gold, it is directly related to how many monsters you kill.