My problem with this tactic isn't so much that I disagree with the freeform economy that FFXI represents, but rather the fact that a few privledged people can short circuit this economy by taking advantage of an artificial shortage in certain supplies to boost their profits with little to no recourse by your average player.
2 examples:
Silk Thread - Sold for 14k/stack at AH, people saw this, harvested up tons of silk, with 100+ stacks on auction the price went down to 9k/stack. The economy works!
Mhuara Gharlic - Sold for 150 in shop, 600 in AH. Only place I've ever heard of to get it is in the shop (if Kolshushu is under beastman control)...however some jerk buys the shop out in less than 3 seconds every time the shop opens. Despite attempting to purchase _1_ bulb of garlic I am utterly unable to get a single one after 6 tries. Is the economy working here? NO! One person who is gifted with either a very fast connection or is possibly cheating is cornering the market on garlic using a method that requires no real skill or commitment.
However, there is a simple solution! Rather than limiting the guild to, for example, 8 bulbs of garlic per day (or whatever rediculously low number there is), why not limit the shop to 1 or 2 per customer per day (for rare items, more for common stuff). Players who want to resell their supply can do so without harming other player's abilities to get at least a little bit of the item each day and players who just need the items for actual crafting don't need to pay unfairly high AH prices because their connection isn't fast enough to out-buy whomever is hogging the supply.