Larian Studios Forums Divinity - Original Sin Divinity Original Sin - Help/Tips/Tricks Vendor Attitude formula

Hi folks,
has anyone figured out the formula that determines how much you have to pay Vendors to boost Attitude?
I saw the wiki page here:
http://divinity.wikia.com/wiki/Divinity:_Original_Sin_Bartering
say that it's 20GP per point for every vendor except the Teller of Secrets, but I found that some vendors like Arhu and Daremos also require 200GP per point. What decides this?

Vandervecken

I think their level.

Ok, but what are the details?

If I had the details, I would've posted them. Perhaps you would be interested in finding out the details and updating the wiki?