How do you deal with constant undercutting?

[Liam_Harper]

I don't have much of a problem with undercutting, except when it's excessive. Lately, I facepalmed over some guy trying to control the mame shiba market. Dude was selling like 10 of them, all at the lowest price. As usual, I sold mine a bit onver the minimum. Next day, price had been cut by 20 000 gils. Just this time, I undercut by a mere 2 000 gils to see what happens. 10 minutes later, he had cut all his shiba by 20 000 gils. I don't understand those people.

Sometimes it's an aggressive "get off my market" tactic. He wants you to see that if you undercut him, he'll drive the market into the ground, thus hoping you'll give it up in disgust as unprofitable and move to a different market.