Whenever I see someone trying to buy in bulk it makes me wonder what they are up to. They want that item for a reason. When they are asking near market value it makes me wonder even more. In the markets I work, its easy to spot what they plan to do with it. Some supplemental items tip you off.
If I see someone asking for adders/lichbloom/icethorn I think inscription. If they add eternal life I know its for darkmoon cards. If the request has frost lotus, he is an alchemist. If they are working the darkmoon cards, I can offer them snowfall ink. If he is an alchemist and is looking more for icethorn and lichbloom at the right price, I will offer him some of mine.
Next time you see someone asking for something in bulk, try to figure out why. Either he has a market he is working or its for personal reasons. Your competition could be tipping you off to a big market that you don't know about yet.