Getting Luxon/Kurzick to sell to you?

How do you get Luxon/Kurzick to sell to you? Do you need to be in their alliance in your guild? Or do you just need more faction of their kind currently in your hero window? Thanks.

You just need enough faction. Our guild isn't allied with anyone and once I got enough faction the kurzicks were fine with me. The luxons were too, before I murdered a load of them and did some kurzick quests