Faction is playing a role in pricing. Just found an Apprehensive vendor.
Code:
[Sat Jul 17 22:42:28 2010] Boomba the Big looks your way apprehensively -- You could probably win this fight.
[Sat Jul 17 22:42:34 2010] Boomba the Big tells you, 'I'll give you 4 platinum 4 gold 9 silver 1 copper for the Ebon War Spear.'
[Sat Jul 17 22:42:45 2010] Krystin Charcoal kindly considers you -- she appears to be quite formidable.
[Sat Jul 17 22:42:46 2010] Krystin Charcoal tells you, 'I'll give you 4 platinum 5 gold 7 silver 9 copper for the Ebon War Spear.'
So it looks like things are working ok on the faction and charisma side of things, however that does still leave individual vendor price discrepancies in the air, but I have one more test to run to verify those.