Currently, the Auction House defaults the amount of items to purchase to the amount of the item sold. I think it should default to 1. It coild also have buttons such as +10, +100, +1k, and Max ti increase the bought amount without typing. This would be helpful because, a majority of the time, people don't want to buy everything for sale. One time I accidentally bought 30 yellow beads instead of 1 due to the default, and, as a poor player, iy took all my money I was planning to use oj rune armor. I was unable to sell them back.
Another nice feature would be a calculation for the price of however many of an item you enter. I'm no expert, but I beleive that should be as simple as using the equation XY, With X being the amount of items and Y being the price per Item.
Thank you for reading my suggestions!