The honest way that I make money is to have a rogue with high lockpicking and a priest with high artifact skills. Selling unID'd stuff nets a 50% loss and not opening chests is self-explanatory.
I also packrat and go to town to sell off a lot. If I'm full and find a wandering npc I sell what I can to them and collect more crap.
To be honest I was pleased with how well W&W did the gold. Most games start out with your party in poverty and then by endgame you have way too much. I never felt strapped early on and now I can always train in something when I find 10K burning a hole in my leather leggings.
Not sure if this helps, but gold can be made honestly if you're thrifty.
