Ok, so you surely don't expect us all to share our economy secrets, do ya? 
Anyways, a couple of simple tips could begin to make the difference, although I am not one of the richest around, and not even close to them: -Don't waste money. Don't play roulette or cards with bets on, unless you do feel very lucky. If you take a look at players' profiles, you'll find that the great part of them is in actual loss against the roulette. More than ever, don't look at gambling as your primary way of income;
-Don't buy too many arts. Refrain from the wish to have a full set in a short time, everything comes in a long time while playing this weird game. Think about what you really need and save the rest;
-Try to enroll in production facilities. Keep an eye on those who work a lot and have a lot of cash, and try to get the elements they need to be sure to enroll. The economy may change from time to time, but some investments seem to pay more frequently...go check out for them, don't want to spoil you the fun ;
-Don't just enter any hunt you stumble upon. Only fight monsters that can at least repay for the durability of the needed Artifacts, and pass others. Try to find some reliable hunters of your level and help each other with hunts, this way you will hardly lose hunts;
-Calculate the cost of Artifacts per battle, and choose the cheapest way to match required AP with durability loss: by the way, binghuo has posted somewhere his suggestions about this on the forum, and it seems to work. I know it could be a nuisance to do the calculations every time, but if you spend a minute on every Art and write down your notes somewhere, it will be muh easier for you to exactly know how much gold you are spending per every battle;
-It's best to sell back any broken Shop or Facility Artifact rather than getting it repaired, unless you find a cheap offer. Only have rare and needed Hunter Artifacts, Enchanted and Thieves' ones repaired, since they are hard to lay your hands on often;
-About Mercenaries' Guild: this thing takes a lot of time, as everything else. It was once easier to climb their reputation, now it becomes a loss of money. Fight your way up to level 2 and get the extra primary parameter, then you'd better slow down with Merc and focus on something else;
-Avoid buying resources or other stuff on the Market. Try waiting for workshifts and buy fast as hell, or try to get some on lease asking to clanmates. If you are in dire need of resources and can't get them, you can try and ask me, for instance. If I have the required resources and can give them away, I will sell them to you at basic price. And maybe other clanmates could do the same;
-Finally, roll up your sleeves, hold a glass bottle on its neck and crush it, then get ready to brawl at the market!
P.S. I am a Wizard like you, and I can understand your problems very well! Thumbs up man!
