Considering there is some slight new UI elements in WoW classic. Here’s mine.
For items that are unusually priced very high for that item, a new confirmation dialog box should pop up when someone accidentally goes to buy, out of real life mental distraction reasons/tiredness, one of these items and this new dialog box should be moved from the usual confirmation dialog box position on the screen to break the mouse cursor routine, alerting the person, but also, incase this person is far gone in their mental ways and goes on to still click the new position confirmation box with ‘yes’, the ‘yes’ needs 3 seconds of being held down. This new box will be highlighted red of some sort with a warning and the price largely highlighted.
This protects innocent people who are undergoing some mental thing and makes buying quickly on the AH feel safe! And still allows the principle of someone listing items to a higher degree than normal for said item.
This new confirmation box should be on by default and can be turned off if those wish to. I say it should be default, because seeing how it’s rare someone wants to buy items x800 their normal price, this new dialog box with a 3 second hold to confirm, will rarely be an annoyance.
I think leaving this to addons is a bit flaky. Not all players are aware of these addons, some prefer a more pure experience, you might say well, a new UI element ain’t pure, well, as explained, it would rarely ever pop up, can’t be seen as a new element unless triggered, and it is a much lower footprint than an addon, and comes from the devs themselves.