First off i take no credit for the idea it all goes to Derek's Gold Mastery Guide... but i would like to tell the people who dont have this guide a great idea from it.
It doesn't take much money unless your servers economy is really messed up and lvl 1-20 weapons cost like 30g.
The idea is to buyout every Item that its from level 20 and under that isnt overpriced since alot of lowbies post greens for 13-30s.
Then you can resell the items for 1-3g depending on the item. Sometimes even more. But, you have to make sure to keep buying the stuff people put on for extremely low because if your stuff is there for 1-3g and someone else is selling it for idk... 5s then yours will never sell.
Ive only been doing this for about 3 days but ive made probbaly over 50g over just reselling lowbie items and since its such low lvl items it doesnt cost much to anything to resell them if they dont actaully sell.
The main key of this to keep buying the people that undercut you or else your stuff wont sell and your money will go to waste.
*disclaimer*
I will not be held responsible for any attempts at this that do not work out
Hope it works for you as well as it did for me