Due to the simplicity of the in-game economics, anybody with a decent Guile score (around 3 or so) and a half an ounce of patience will be able to buy anything in half an hour.
The easiest target for this cheat is the guy in Bowerstone South right next to the entrance. Buy out all of his potions (health, will and resurection philes). The more of these items you have, the faster you make money. About 25 of each (except res. philes, you can only have 9 of them) is the best to start with. Since the price of each item is based on how many the vendor has in stock, when he has none, he'll pay a fortune and when he has a lot, he'll sell them cheap. You don't even have to stop talking to him. Just make sure that when you sell, you hit the sell all button because selling in chunks drops his buying price. Once you've sold them all, buy them back all at once at his reduced price and repeat the process.

I discovered this cheat with a little over 9,000 gold earned the hard way, and in 10 minutes I had 100,000 gold. I then visited every shop I could find, bought the store out of their potions (wound up with about 230 health and will) and in another 10 minutes of exploitation, I had 700,000 gold. If you can get a bunch of wedding rings, you can speed up your profit level even faster with that same shoes in Bowerstone south.