They are probably trying to get the buyer to accidently grab their 30z master red while they fast purchase a bunch of master red stacks. Another one would be the intention is to trick the player thinking it's a cheap 20z stack of reds so they will buy it quickly without checking how many reds are in the stack. Either or it's a scam plain and simple and merits punishment. Hiding in AH will not make you immune from the lawman and the way to notice scammers is to just check the market values.
I had to highlight all the important parts about your argument because here is the thing about the accusation of said scam - if people take a few seconds and look at what they are buying than there is no issue.
I don't agree with 'pricing gouging' but in the same instance if people are willing to buy their items at ridiculously overpriced rates than who am I to say that they should be punished. Whether or not the seller intentionally priced it or just too stupid to check the current market prices is not my concern. If something is being sold on the AH and you carelessly press the buy out button without looking at what you bought than whose fault is it? Let's all grow up here for a second and take responsibility who pressed that button - cause no one made you do it. Until there is actual rules in place for 'price gouging' and the market is regulated by a government body in the game than the AH is a completely free market for anyone to post any item in their for any amount no matter how stupid high it is.
All I can say is take that 3 seconds to look at what your buying - confirm what your buying and once you understand it - hit the buy button. I do this all the time and I have never accidently bought any over priced items.