How do you deal with constant undercutting?

[SinSiew79]

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.

can you send that guy to Luisoix?