ZOS have seriously broken the trading economy with the huge influx of gear and the switch to BoP. You only need gold to by mats, tempers and food/potions, which can all be obtained by farming anyway.
Since One Tamriel I have been doing undaunted dungeon pledges (just Maj & Gilerion) every day & I have racked up ~200k gold doing so. I only spend gold on armour repairs, horse training & the listing
You can buy mats and sell crafted items, like Potions and Glyphs, those are the ones that usually sell. You can try your luck buying raw mats and sell gold tempers.
For a modest fee of, let's say 100.000 Gold, i will teach you the secret to making millions. Just email the 100k ingamge to @getscammed, and i will sent you the tutorial video, on how to make millions