If people wanted to flood the market like that (which would be stupid anyway) they could with an extra character or so on. That wouldn't benefit the market flooders, either. Farming for my own stuff, stuff for friends, stuff that gets npc'd. DoH can flood markets (and do) like noboby's business. if its already easy to flood the market, then let's DROP THE FATIGUE~ You can only gather 30 times now before you gotta change! lol.... If its already easy, then the system must be ineffective as is.

As an aside, people doing DoH leves can flood markets, too. albeit it less often.