You should get plenty of skill points from mindreading, so can boost/max the associated skill to reduce the cost.
Maybe the programmers got tired of round numbers for gold rewards, or decided when balancing the add-on to change all the gold by a certain percentage, or something.
Legionangel's
FoV Walkthrough doesn't appear to list quest rewards (didn't look very closely, since I have not gotten that far yet in DKS), but you could check the
Divinity 2 Wiki. Post your gold amount rewards for a couple quests, and maybe someone else will check what they got.
