I'd like to see something removed from the site!
The bloody price indexes for the AH on items!
The reason is very simple: every server is an economy on it's own, with different ratios between the various races, classes, levels, instances/raids run, being Horde or Alliance side, and of course the randomness of what's being dropped. Not to mention that the amount of goldbuyers is very different for every server as well (prices tend to rocket skyhigh on servers where many kiddoes buy gold, nice way to mess it up for others, even on other servers, I'll explain in a few).
Now what that mean price thingy does, is equalize between all the various servers. There are servers where people put equipment on the AH with a certain price for NO OTHER REASON then because "allakhazam says it's worth XXX gold". That's complete nonsense! On some younger servers, the price of a mooncloth bag might be a lot higher, because there's only one or two people who can craft em yet, while on others, every clothier and his dog can make one on a daily basis, with the help of some alts that do no more then produce a mooncloth every 4 days. At the same time, on some servers a basic piece of tribal gear isn't worth a thing, simply because there's hardly any druids, and the ones that are there do their own LW. Pricemechanics should apply there, and lower the value of druid items there. Or supply should just cease for lack of customers. I often see 5-6 Shadowcraft Belts on my server, at the value proposed by Allakhazam. And no, they don't sell.. The only reason for their pricing being, that Allakhazam proposes that value. Compared to that value, the AH-deposit is marginal, so people won't care either even if they don't manage to sell it for over a week. Sooner or later, a goldbuyer WILL purchase the items.
Realm A is not Realm B, so why have this stupid priceguide try to pull them closer to one another? And yes, a server infested with goldbuyers makes things more expensive on that server, increasing the avarage value even further. Not to mention, taking away a lot of fun for the people who don't buy gold, since things will become impossible to buy from them. And these avarage prices will influence the prices on other servers, so a server with goldbuyers will indirectly affect the prices on other servers thanks to this avaraging, ultimately tempting some people on these other servers to start buying gold as well, if they want to get the items they want. Very sad, aye, but I'm afraid this is just some basic workings of the human mind and economics explained here..