This thread is not about the morality of undercutting; there's 13 pages of that discussion here. This thread is discussing strategies to defeat heavy undercutters.
So now that that's out of the way. There's someone on my realm who regularly crashes the JC market for hybrid gems. Every Tuesday prices go up to well over 100g per gem. And every Tuesday this guy posts 10 of each gem for 40g. Yes, 40g, down from 100g, a 250% undercut.
Thus far I've just been buying them, and resposting with my stock. It helps move my immediate stock, but only fixes the problem until he logs on again, gets all happy that he sold out his stock, and once again crashes everything. I can move a lot in the time between buying his stuff and him posting more, but my current strategy is doing nothing but encouraging him to continue this. If I can't grab everything cheap before all the bots start undercutting his 40g, the market for that gem crashes hardcore for a few days. Of course, having to spend 40g a gem to bolster the market is cutting into my profit margin quite painfully.
So...what do I do? Continue buying his stock and encouraging this? Doesn't seem right. Suggestions here?