ok, this trick is really simple.
After blizzard made it possible to trade back items purched from emblems, this trick came up.
You simply buy a item for emblems, equipt it, then sell it back for a full refund. Do this with all the items you need for the achivement.
And remember, if you cant get all from emblems of qonquest, you can always get valor emblems, and buy more from there.