I just sent the following to email@example.com but since it's come up here I thought people might find it of interest. I've omitted the log data/account names but it's pretty easy to reconstruct if you are interested.
I'll preface this with the comment that I know baiting auctions with low priced mats and sniping the people who are tricked is not against the ToS but the behavior I am seeing is clearly that strategy applied via an automated botting program and it's just offensive to my sense of fair play.
Summary of what is going on: There are bots sitting in Booty Bay on 14 servers (high/full pop) logged in 24 hours a day. They operate as the snipers, never move at all, and time out every 30 minutes and relogin within 7-8 seconds. There is also a second account for each server sitting in MOP shrine which logs in every 8-9 minutes and posts a collection of quantity 1 of several different shadowland mats. The sniper bot then buys any listing posted at or below that price leaving 2 items + the original listing. It's been going on now for literally months although mostly you will just see anecdotal reports of it.
I believe the reason it's 14 servers is there are 16 wow accounts over 2 battle.net accounts, 2 of which round robin the baiting accounts and the remaining 14 run the booty bay bots. I suspect the relisting is also botted but that's not totally clear - it is done by other characters in each guild which are also sitting in shrine.
Other circumstantial evidence I saw: guild <redacted>-Zul'jin has a bunch of leftover sub rogues which I assume were used for botting in the past but are now banned or retired but it's definitely symptomatic of past bad bot behavior. Also the booty bay bots all have their away message as eg " is Away:离开" which I guess is Chinese for "away" which tends to confirm it's all one overarching owner.
Here is a table of the accounts and guilds for each server (here cycle is the time gap between logins for the bait account measured over ~ 2 hours on 5/30/21, STDEV is the standard deviation of login time gap). I have looked at the rest of the servers as well but did not retain logs. Needless to say it had been extremely predictable over the time I have been watching though I think the botter has added servers in the past month and at one point was only doing round robin with 1 account.