Dude, they're selling him beard care products. I mean, with a name like Proud Beard, what else would he want so much of?
Ok, seriously, this is going on on all servers except Odin and Bahamut (because they have disabled new characters). What's going on is that they are NPCing stuff gardened from wildgrass seeds. Expect a nerf in the resale prices of wildgrass products in the next patch.