Well, they do think you are part of a prophecy so you get really good deals. I also noticed that they buy at extremely high prices so I sold off a lot of things (though I did not think to buy back).

Possible spoiler? Or just a freak incident.

I don't know what experiences others have had trading with the priestess in the Sahaugin City, but when the Paladin (charisma 21 -- nymph cloak and blade of roses) leading my party (reputation 20), went to trade with the priestess the paladin was able to buy cheaper than he was selling -- no stealing involved. Selling a wand of monster summoning and buying it back netted about 9,000 gold. Selling a rogue stone and buying it back netted about 2,400 gold. I racked up about 75,000 gold before I decided that I would never use much more.

Jon:thanks for telling me you have money on your characters. ripper and
spedo go get them!
Father Bronze: Don't worry G.W come with me!
Father Bronze: Dimension Door
Jon: NOOOOOOO!! They escaped! hehe nice story. Thanks for the tip! Now I know how to get rich!