yes i forget this option, I think that currently there are 3 or 4 options to do zeni without buying cash ,
1. farm and pray for a purple or green stone.
2. farm and pick everything to be able to craft item lv 70.
3. Buy and resell the action house or the stores of the players
4. use your T point to upgrade a gloves or clother lv 30 to +13-15 to sell this.
For what ive heard, youll need at least 30kk and more to get high level on craft. And also you need a good amount of zeny if you wanna play the AH, because is the possibility that you can lose much money. These things demand a lot of time. If yu are not a casher, youll have to work your ass very hard and spend hours and hours per day to get decent money for your char. And its very unffair for me, cashers have so much privileges now, thats one of the reason I stopped playing. But lets see how this goes when the game is official released, when everything is fixed