Wait... What?? That's right! It is possible to compete with yourself, but not in the way you compete with others on the AH. This is definitely something that you want to avoid. I will be covering this subject in three parts, maybe more, but the plan for now is for three.
In Part 1, I will cover basic factors to consider when choosing how many of a certain item to post. More specifically, I will be using the 77-79 Cataclysm greens market as an example since gear is pretty expensive to list on the Auction House and is commonly re-listed.
Listing Too Many of One Item
One of the most common mistakes I find on the AH is when people list a wall of crafted items that are the same or almost the same. For example, with Jewel Crafting, someone will list 10 Brilliant Primordial Rubies at one time. While these are quick sellers, the market is ripe with fierce undercutting, and it's highly unlikely that this person will sell all 10 without having to re-list multiple times. Listing auctions costs gold, gold that you lose when you cancel your auctions to re-list them. You also lose this gold if your auctions don't sell. However, you do get the gold back if the auction does sell. If you're using an add on that tracks your sales, look at your sales history for an item or item set that you sell. How many sell at a time? How often are they bought in that quantity? Who is buying them? Which days bring higher sales, and which days don't. These are all good questions to ask yourself when looking at consumable items that you sell.
Consumable items are any item that, when used (consumed), are unable to be used again. Some examples of consumable items are:
Potions, Flasks, Elixirs
With these items, you don't want to post too little, and lose sales, but you also don't want to post too many and waste gold. Posting too many of one item, costs more time to cancel, collect, and re-list. Time can either be your friend or your enemy, both in WoW and in real life. For the most part, time is only your enemy when you are inefficiently managing your time.
Gear is Expensive to List - Do it Wisely
Not everyone has time to do in depth research and analyze numbers, stats, etcetera. Add ons do reduce the amount of time you need to spend researching but they don't do everything for you. Knowing your items and how to sell them is important. If you understand this, and use this knowledge to set up your add ons, you'll waste less gold by posting too many of one thing or too many like items.
Cata and MoP greens are popular markets which this applies to, so I'll use them as an example. Many gold bloggers who are active in these markets talk about how to price them so they sell. They give general guidelines for purchasing too. With this knowledge you can go one step further and sell appropriate quantities. For each armor class (plate, cloth, mail, leather) there are different types of classifications (healing, tanking, dps). Furthermore, you are most likely going to sell more dps gear than healing and tanking gear since a majority of players choose to dps. Alternatively, some healers and tanks may also choose to have a dps spec and gear for the sole purpose of doing dailies quicker. You generally want to post more dps gear and comparatively less healing and tanking gear due to this factor. There's more to it than that though. Below is a breakdown of each type of gear and how many different class specializations can use it. The higher the usage number is, the higher your chances of selling the item. You can tailor your auctions by using these numbers with respect to your realm population and competition. Also, you may want to segregate your gear by number of stat modifiers as well. 2 Base stats +0 secondary, 2 base +1 secondary, 2 base +2 secondary. All of these sell, but I have found that they all sell better when priced differently. Also, AVOID selling items with one stat or stamina plus a secondary stat. I've been watching 'of the beast' modified items sit on the AH for weeks now without budging. I should probably be nice and let the seller know what he's doing wrong, he's likely to have already paid in AH fees what he's asking for the items.
Tank - 3 ( Blood Death Knight, Protection Warrior, Protection Paladin )
Heal - 1 ( Holy Paladin )
Dps - 5 (Death Knight - Unholy/Frost, Warrior - Arms/Fury, RetributionPaladin )
Heal (spirit) - 2 ( Restoration Shaman, Elemental Shamans will sometimes buy this )
Dps (agility) - 4 ( Hunter - Beast Mastery/Marksmanship/Survival, Shaman - Enhancement )
Dps (intellect) - 2 (Elemental Shaman, Restoration Shamans will sometimes buy this )
Heal (spirit) - 3 ( Druid - Restoration, Monk - Mistweaver, Balance Druids will sometimes buy this )
Dps/Tank (agility) - 7 ( Druid - Guardian/Feral, Rogue - Assassination, Subtlety, Combat, Monk - Brewmaster/Windwalker )
Dps (intellect) - 2 ( Druid - Balance, Restoration Druids will sometimes buy this )
Heal (spirit) - 2 ( Priest - Discipline/Holy )
Dps (non spirit) - 7 ( Priest - Shadow, Mage - Arcane/Fire/Frost, Warlock - Demonology/Affliction/Destruction )
Cloaks and Jewelry
Heal (spirit) - 17 ( dps sometimes buys )
Dps (intellect) - 17 ( healers sometimes buys )
Dps (agility) - 11
Dps (strength) - 5
Tank (agility) - 2
Tank (strength) - 3
Things to Take Note Of
Remember that there are 2 ring slots, so whatever number you decide to assign as your maximum posting amount for one gear slot, should be doubled for rings.
At the 77-79 level range, some players are wearing heirlooms, but not all of them. Gear for heirloom slots will still be sought out in order to get a quick ilvl boost from having the gear in bags and not equipped. Boosting ilvl is important for getting into the Cataclysm dungeons as early as possible.
On average, I spend about 1k per day on AH fees for gear alone. I'm writing this because I want to cut down on those fees without cutting down on sales. 1k per day doesn't sound like a lot, but that is about 30k per month or 365k per year. Keep that in mind when deciding on whether it's worth your time to do a little organizing.
Remember this is to intended to set posting quantity limits per item slot as well as item class/type. And this same thing can be used for the 83-84 MoP greens market.
Summary and Continuation
I feel this can be used to get a general idea of how you can cut back on your AH fees and improve the organization of your auctioning set up, specifically for the green gear markets. In part 2, I will be using wow.realmpop.com to get an in depth look at the gear category balance of the customer base for 77-79 Cataclysm greens. And finally, in part 3, I will show how I will be setting up my auctioning groups for these greens, using TradeSkillMaster. In the long run, the time spent doing the research and setting up your groups and limits, will pay off. At that time, you should be spending less on AH fees and less time re-listing failed auctions for these greens. I hope this helps you (and me) spend less gold than you need to, in order to sell your greens.