The auction house is great for when I can't gather materials I need for whatever reason, for when I need stuff in a hurry, or for when I am feeling lazy {and nothing is wrong with that}.
Right now, I'm working on making eggs for the achieve. I'm focussed on butterfly eggs until I get no more XP from them for one "day". I am totally busy getting ready for the real life holidays, and I have figured out how to work and play at the same time. This doesn't allow for gathering, only creating. I needed tiny bubbles, and blue bubbles, and i was going so out of energy just making the bubbles - TO THE AUCTION HOUSE I GO!
And there she was, Nymity, someone selling the exact bubbles I needed. The *only* person selling them premade. WOOT! And every time I bought some, she put more up! Finally, I decided I needed to thank them in "person" so i did a bit of profile stalking, went to where she was, and thanked her explaining why.
The system works. She helped me, I helped her. Sure, i could have gathered and made them myself, but this was far easier for me. This is the user vendor concept in action. I can totally see what TS are trying to do in removing other items from vendors. Sure, this time it was a gathered material, but it could just as easily be a tool, or potion. Herbs {which we all know is a drama fest these days to grow in community gardens}.
{Also, thank people who help you when they don't know they are doing so, it makes the community nicer!}