I feel like this needs to be said - different buyers have different needs, priorities, and pickiness when it comes to spending habits.

Don't just assume that being at the top of the list is the #1 priority if the item in question is selling in stacks of 99 and you're going to put it up in groups of something like 5. If your price is reasonable and you're offering a small quantity of the item, that's incentive alone for many people to buy from you and not the others.