The creature has no loot... You can not kill venders in order to prevent players from using them. I think a GM would make a special case descision if its not.,
If people are buying Krono to work around this A-hole - forget about any SOE intervention. But since the plat is not high enough to matter much for Krono sales - I'd expect it's actionable. -R
If I can get warned for killing a quest npc in goru`kar mesa, then these people should be banned for monopoly'ing blood flowers