I've been having what is apparently a scaling issue caused by inflated secondary stats on some Wrath of the Lich King items. In particular, my Highmountain tauren warrior leveled through Northrend and picked up a green, iLvl 87, 2h sword. All of the secondaries were in the +25 to +30 range, and the Dugi Gear Advisor decided it was better than the heirloom 2h axe I was using. So I went ahead and equipped the sword.
Brewmaster: Hot Trub - Purifying Brew deals 30% of your purified staggered damage to all enemies within 10 yards. Mistweaver: Way of the Crane - Increases your Physical damage by 25%, you remove and become immune to all snare and root effects and you heal up to 3 nearest allies for 150% of all damage done. Lasts 15 sec. Windwalker: Reverse Harm - Heals a friendly target for 8% of their maximum health, and causes 100% of the amount healed to instantly be dealt to the nearest enemy as Nature damage within 5 yards. Paladin
If you're looking for simple, just get actionator. Set it to undercut everything you post for 1c and alt click from your bags. It will place the item on the ah window, do a scan for that item and autoset the price for how much you told to undercut (you can change it accordingly if you feel like it). It will remember if you do stacks for which items and replicate it everytime.