If you aren't among the 100 cheapest listings of an item, nobody is going to want to buy from you anyway, so it's a moot point.

Now list an item 100 times. (So 100 seperate listings for that one item) say list them all for 1 gil (Example). Then go check the market board. You will ONLY see your listings for the 1gil. You will not see any other sellers. This effectively corners the market board and prevents any other sellers from being seen for that item thus denying their right to sell.
Absurd hypothetical situations aside, the obvious solution here is to buy them up yourself and resell. (This is why you won't ever actually see anyone doing this unless 1, the item is already worthless, and 2, someone is extremely bored.)