it seems that for most people, 5 is the most choices they can consider without getting a headache. I think optimally you want the person to narrow it down to 3

it seems that for most people, 5 is the most choices they can consider without getting a headache. I think optimally you want the person to narrow it down to 3 choices, because at that point the person is a lot more likely to buy, since they are at a point where they can consider the items side by side and actually make up their mind.