I hate it when people roll Need for seals. There are better ways of getting seals than dungeon loot, so if they're rolling for that purpose then they're probably not running the dungeon just for the sake of getting that item, they're probably just doing their dailies and grabbing a bonus while they're at it. People who will actually use the item, whether as an upgrade or for glamour, is less of an issue for me.

That said, if you want a particular piece of gear, say so at the start of the run. If you're lucky, the others who can Need on the item might agree to let you have that one, especially if you offer to give them exclusive Need rights to everything else. And then stick to any agreements you make. If they break their word on the matter, I'm pretty sure that's a bannable offence. If you're unlucky and they say they'll Need everything they can, or that they also want it, or they just ignore you... well, you tried.


And if someone in your runs says they want a piece of gear that you can Need on, consider it. Don't ignore them; that's just plain rude. If you want the same item, say so politely. If you don't want the item for any reason, reassure them as such for the sake of their peace of mind if nothing else, that's just a nice thing to do. If you want it but only for seals, well, you can get seals in dozens of other ways including other drops; if you really have to get seals from drops, please make an agreement that you won't roll Need on that particular item, if they don't roll Need on anything else. The odds are still in your favour that way, and you get multiple shots at something you want. And obviously, report them if they break the agreement.