This can be obtained by using the in-game console. Hit your ~ key and type this command to add gold to your inventory. (This can be any amount you wish, but you must have 100,000 for the achievement)
player.additem f 100000
That is the fastest way to obtain this achievement. A more legitimate way of grinding it would be alchemy. Once you get it leveled up a bit you can buy ingredients worth 200gold and turn it into potions worth 600 - 1200. An example of an easy potion with cheap ingredients would be the Salt Pile + Deathbell combo. You will easily profit 10x what you paid for the ingredients.