A buy order would allow sellers to come back to the city, check the AH, and withdraw their gold immediately if they like the price. These orders would be posted by people who need farmable goods, and since the first buy order to be filled would be the best-priced ones, there would be more competition between buyers.
Right now, the people who have to compete the hardest and tie up their money are the farmers. Their buyers typically have many times more gold than them, and get what they want with no uncertainty and no waiting.
Of course, buy orders don't work for everything. I imagine that there will always be both auctions and buy orders for everything, and anyone willing to wait a bit stands a better chance of finding someone in a hurry. Buy orders would also help people who are trying to find rare items. Instead of having to stalk the AH from their cell phone at work looking for that elusive mount or rare recipe, they can simply keep an attractive buy order posted at all times.
The AH interface
Speaking of the mobile AH, it's time that the in-game interface inherited some of its features. Right now, most people still use the default UI, which won't save searches, can't categorize very well, and sorts auctions in the least sensible way possible by default.
Anyone who takes the time to install and learn any AH addon has a significant and, in my opinion, unfair advantage over someone using the basic interface. They spend less time finding what they need or posting auctions and are less likely to accidentally post something for less than they intended. There have been other parts of the game where addons used to be absolutely necessary, and almost every single one of these has led to an interface upgrade so the general population can compete (like when the default Arena frames became less terrible).
I understand the presumable business appeal of making the better interface hidden behind a paid feature. If the reason Blizzard hasn't made the in-game interface stink less is because anyone can opt to pay and get a more functional tool, though, I'd like to point out that the mobile AH doesn't officially support modifications like the in-game one. It's basically useless to serious AH users. It allows us to stalk rare items and repost a few undercuts, but it's not a serious competitor to the in-game experience of Auctionator or TradeSkillMaster, with its limit of 200 actions per day and the fact that it takes so long to do anything.
Blizzard raised the gold cap in Cataclysm, and for every gold sink it introduced, it seems the designers made three more ways for gold to be created. On the surface, it doesn't sound bad; the gold being created is always spread across the general population, so it seems to be designed to spread the wealth. The problem is that in-game wealth, no matter where it starts, tends to pool on players who play the AH.
Again, that doesn't seem too bad, right? Some players may have millions of gold, but overall everyone has more gold so can buy more. Unfortunately, that's not how it works. The number of dailies it takes to gem and enchant an average raider's gear has gone up, not down. In essence, people who don't hustle for gold will have to work more now than they did in Wrath or earlier just to keep up with the basics. Also, the goods a little higher up on the hierarchy of needs like BoE gear, offsets, mounts, pets, etc. are farther out of reach on average unless you work at maximizing your gold per hour and dedicate some time to gold making.
There are two solutions. First, make more gold sinks. Make them target people with large pools of wealth -- maybe some sort of incredibly expensive in-game cosmetic bling that would appeal to people with gold-capped bank alts. How much would Fox pay for a floating golden top hat that followed him around and told others how amazingly good-looking he is? (OK, I'll level with you: I'd make a terrible item designer, so please take this as an invitation to fill up the comments page with ideas about how to separate the gold-capped from their wealth.)
Second, and possibly in addition to gold sinks, introduce more BoE items on the Blizzard store. Every time someone buys one of those and sells it for cash, it spreads the wealth around.
Maximize your profits with advice from Gold Capped. Want to know the very best ways to earn 10,000 gold? Top gold making strategies for auctioneers? How about how to reach 1 million gold -- or how one player got there and then gave it all away? Fox and Basil are taking your questions at firstname.lastname@example.org and email@example.com.