Depends on how much time you have to sink into this game. You better off with other MMO if you value your budget and time to be honest lol. You can usually make 5-10m a day running OGH, Mora coins, and selling reset stones ( which I don't recommend). Eden badges are best saved up for KVM gears. While doing mid-TI, greeding is your top priority above all else. Mid-TI often have very good cards to sell and the loots can be pricey.
You used to be able to hunt cards like Raydric and sell for good chuck, but the bots pretty much ruined all that.
The cost of one decent gear class at 300m-1B are simply unreasonable for casual or even hardcore MMOers to be honest. Best way to make zeny is not to spend zeny at all. Just make a support class, and you hardly need more than 50-100m to enjoy the game. You're also constantly getting parties, and people generally welcome you, which I think is really the point of playing MMO.