I wouldn't say I'm rich, but I guess I'm well off. I have been on Gaia for over two years now, so many of the high priced items I own I got when they first came out. All of the letters I won I bought when they first came out. 5k is the most I ever paid for one. Then I just hang on to it and wait. I've only seen one letter that's gone down in value; May 2004, but it's going up now too. Here is my advise for making gold:
1. Get donation letters. Either donate or just buy them from other users. I donate, becasue of how unstable the exchange can be. You can find deals if you look often and are patient, but you can get screwed big time.
2. Post. You get gold for that, like 10-20 per post. You get less the more posts you make, but it resets every 12 hours.
3. Take Polls. You get 10 gold for every poll you answer. But like posting, it starts to go down the more you take. This also resets after 12 hours.
4. Sponser Links. Did you know they are still around? Do you even know what they are?
Go here to find out.5. Reviewing Art. You get gold for this too. I don't do this, so you're on your own here. Head over to the Arena in Barton if you're intrested.
6. Link List Reviews. I think this still works. You get gold for reviewing a link in the link list. I seem to recall it was 35 gold per review, but you could only do one or two per 12 hour period. I heard a rumor that the link list was going to be taken down though.
I can make 100-200 gold a day with only being on Gaia for about and hour or two. I suppose I could be more aggresive and make more gold per day. I've made about 1000 gold a day during an event from being on all the time.