Its a free market and if they want to they are free to undercut to even lower than vendor price, just because they keep a close eye on their auctions is no proof that they are bots.
In my opinion you undercutting by the amounts you have is way more despicable than someone trying to get their wares to the front of the line.
If you undercut me like that i would make it my mission to see that nothing you post would ever sell.

Also showing their names is against the ToS, and trying to get your competition banned with no evidence lacks honor.