If you haven't taken a chance to look at this thread, you might want to read it from the d3 forums.

Max bids not confidential


"Have you ever wondered why you pay the max bid on items you purchase? It's because the AH gives away this information freely.Every bid goes up 5%. When the bid doesn't go up 5% you've reached the max bid. For example, people like me who put up a round number max bid make it blatantly obvious. Let's say I put a 100,000 max bid on a 72,592 item. All the seller has to do is shill up to my round number and stop. Here's what the bids look like: 72,592 >> 76,222 >> 80033 >> 84035 >> 88236 >> 92648 >> 97280 >> 100,000 (instead of 102144; Max bid reached!)Here's a simple solution: Make ALL the displayed bids 5% higher. Or is this working as intended? I've been burned so many times by this already. Don't place max bids!"

I can't take credit for this - Edicted from the d3 forums posted this - but everybody here should have a good read about this. Any discussion to follow can certainly be done here.

Thanks for the link!

All the talk on that thread is about how the bot has to bid in increments. There is plenty of data being passed to the computer before it hits the computer screen. A good hack or bot shouldn't have to use the click interface. When the Auction House first went live, there was information about the item being passed with regard to the number of affixes on the item that could be extracted and recorded with a utility outside the auction house. I doubt that's the only piece of information being passed back and forth.

Heck, the maximum bid might be indirectly sent directly to the bidder's AH client, in the first place, so the bot would know what the max bid is and only have to bid once to hit the max bid. If the people on the forum aren't trolling, it's pretty obvious there's something going on and I doubt it's anything as complicated (or straightforward depending upon your point of view) as having a bot bid up an auction. I never bid above what I'm willing to pay anyway, but this could be rough for someone that isn't so careful.