I can't find the link to the rules about spamming but I read somewhere that repeatedly bumping your own thread was not allowed. Some of his threads are 15 posts of nothing but him.
I personally do not have a problem of him having many threads for auctions but bumping auctions that ended months ago just seems silly.
He's not just bumping -- he's also adjusting the price, which is more meaningful than the typical "bump reply". So that guideline (no more than once per day and a few times in a row) doesn't apply.
It may be excessive, though. Not really auctioning, either. But it seems like most people here aren't bothered by it.