You can make gold in World of Warcraft without addons. You can also PvP and raid without addons; however, for the vast majority of people, that would result in lower performance. Unlike PvP and raiding, however, there is absolutely no way to use the default UI to be as productive in the auction house as you would be with addons. The default Blizzard UI for professions and the AH was not built for making money.
I divide gold addon users into two groups: the people who want everything to be as efficient and streamlined as possible, and the people who simply want to be able to do basic tasks without as much hassle as the default UI imposes on us. Let's call them "power auctioneers" and "retail auctioneers." What addons are available now, and how can you use them to accomplish your goals?