Okay, I've seen quite a few complaints about the gold being scarce in-game, especially due to later-leveled skills costing upwards of 3-4 gold per level. There isn't really a "quick" way to make gold, so if you're looking for an easy way out..well..one doesn't exist. It takes effort to be a "rich" player.
So I'm sure you've all seen that the prices are somewhat reasonable in early-game, just high enough to make sure you have to focus on one class for a while, but you can still afford nifty things like book quests and dyes. But as the game goes on, if you aren't making any real effort to keep your coin you might find yourself losing it often. Some things that newer players might not notice at first...
-Upgrading using scrolls does cost coin to do. So does fusing items such as treasure map pieces. You don't want to just spam upgrades, save your scrolls to use on some equipment that you think is going to last you a while. Remember, leveling goes quickly in Eden Eternal. Up until around level 35-40, most equipment becomes obsolete quickly.
-Repairs. A good way to cut down on repair costs is to craft orange weapons, if not including the orange armor sets. Yes, this is costly, but it saves you a great deal since durability falls faster than Wil E. Coyote after he runs off a cliff. I've found it to be easier to save gold if you just either: A.) Swap out equipment often with green monster drops or B.) Invest in the orange weapons/armor.
-Focus. Focusing on one class might seem counterproductive to obtaining tier 2 classes, but it also helps keep the cost of skills down. Since you are only focusing on one branch, or one class, then you are spending less gold than if you were to level all your classes evenly.
-Farming. Run dungeons multiple times after you hit around level 30. Shark HQ gives an awesome amount of coin dropped, and the class experience is rather tasty. Just keep grinding away and your classes (and wallet) will thank you. Just remember the equipment switching tip or invest in orange sets, especially for hard core or long-term grinding sessions.
-Quests. Quests start to give you great amounts of coin and experience very quickly. Repeatable quests are also a must for grinding region fame. Which brings me to my next topic. Trophies. Trophies are not necessary, and while they may help, the ones dropped by Bosses are much more desirable than ones bought in Fame Chests. I didn't notice many trophies that I just /had/ to have from the towns in Open Beta, other than the Limestone and Twilight Hills areas. Not buying the higher-tier trophies will save you a lot of money.
-Stacking Quests Do quests that have the same requirements at the same time. You'll kill two birds with one stone. This works especially well for Book Quests, which reward experience, gold, and rare monster pots. Curia Library Fame usually gives good rewards, at least in GF. I'm hoping they do the same in this game as well. They usually coincide with killing mobs that the "story" quests require you to kill.
-Auction House. If you get a monster drop that doesn't have the stats you want, or it isn't a piece you need, don't sell it to an NPC. They rip you off. Sell it for a more reasonable price to either friends or in the Auction House. The tax rates aren't terrible and it's much more convenient that having to buy World Calls and spend real money just to sell things for in-game coin.
-Guild Quests. I cannot stress this one enough. Some guilds might seem like jerks for making you do rep quests for them, but you shouldn't complain. The quest usually pays about DOUBLE what you paid to buy it from the Guild Reputation NPC. Knocking a few of these out each day with some friends in your guild will make for a ton of guild fame, and very fat wallets. Parties are the keys to getting these done in a quick and easy manner. Just gather a party within your guild who all have the same guild quest.
Follow these simple steps and you'll be on your way to hoarding around 100+g by the time you hit mid-game levels. It's worked for me and it can work for you too.