Gotcha: It still is one of the most interactive games, especially for its time. Not many games come near it. :)
You generally find enough resources to buy anything you want, but if you're in a hurry, then the casino is your best bet, especially if you're a Fellowship member.
Play the Roulette table and move gold towards the color that is about to get hit. Been a while since I've played this mini-game, but you should be free to keep moving your money while the wheel is rotating.
In vanilla, I'd advice against creating huge amounts of gold (and other items), since having too many items in the game-world leads to problems.
Better yet, bet on the races.
Inititally, you can only bet 100 gold, but if you repeat the race without first taking your winnings, you will be able to bet your winnings to get even more money, allowing for exponential growth.
Just remember to save after each round, and reload until you win. This may take a lot of reloading, but it will allow you to grow your gold supply exponentially.
With this method, it won't take long until you get enough gold to crash the game. In fact, sinc e the growth is exponential, it is likely feasible to get even Exult to either run out of memory or lag to the point of being unplayable when using this method.
(If you already have a lot of money, I believe you can save time by betting 100 on all 4 participants the first time; you'll lose 100 gold, but you're guaranteed to have 300 gold on the winner, so on the rematch, you would win 900 gold (if you win).)