Also check out auctionator, it has similiar functions; it combines all same priced stuff into one list, so you can buy out 200 stacks of herbs at 20g each or whatever.

The problem was that the person was putting auctions up starting at 1c, but not putting a buyout. Auctionator is set up only to buyout, not to bid (or at least that's how the default is, I've not looked at it any deeper).

Yeah, on my realm also people have recently started putting bid at 1c and if there is a buyout, it's not worth it. Auctioneer can do bids at minimum, but as the question said, this just means a full mailbox in minutes after everyone else notices the good bid price. So the question is not about buying en masse, but bidding at a bid other than the minimum... en masse.

Honestly, it's better to fill your mailbox than to skip ahead and bid higher. This isn't ebay; your competition has less than 48 hours max to outbid. Convenience always costs. Just wait until it's "short" time remaining to begin the war and good luck. I've bought plenty of stuff at like 1g/stack because of time restraints on bidding wars.