You could and it does make it even simpler (one button does it all) but I recommend against it. You would have to trust the undercut value. Because it also does a scan for the item when you alt click you can see that quite often there will be someone artificially lowering the item price in hopes to drop the price and buy it cheaper. Say some herb usually sells in stacks of 20 but the price for a single unit is 40g, which can go unnoticed (if no add-ons you'll only see the full price of the stack, not by unit) . Someone can easily pick one unit of that herb and post it at 20g or less.
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.
Functionality is the heart of these guides, what you are really paying for. There are a lot of aspects I could look at with regards to functionality such as; questing path; quest progression; addon user interface; bugs; performance and many more. All that we are concerned with are questing path (speed) & user interface. All the other aspects aren’t worth comparing as both wow guides are light in terms of system usage, both have very few bugs, and both update your quest progress in real time.
At level 80, I skipped Cataclysm and went straight to Pandaria. Even as my warrior leveled up, and that heirloom axe increased in iLvl along with me, Dugi still ranked that iLvl 87 sword higher. I kept picking up new 2h weapons, and Dugi kept rejecting them in favor of that Wrath sword. That's when I noticed that all of these Pandaria weapon drops, even weapons 20 iLvls higher than the Wrath sword, had secondaries under 20. So even though Dugi Gear Advisor is showing that a new weapon would provide a DPS increase, it still prompts me to re-equip that Wrath sword every time I equip a new weapon. Meanwhile, I've kept the heirloom axe in my bags, assuming that at some point its stats would once again beat whatever I had equipped, but nope, it doesn't, according to Dugi.