The shoulda/woulda customer is everywhere. They are giving themselves an excuse to not buy, they want the item but they have a budget or some other reason they need to not buy. If you pull out a bigger one then its not blue enough, if you pull out a blue one, the foot is wrong, if you pull out one with the perfect foot, they suddenly get a phone call and wander off leaving you to put away the 10+ items you pulled out of your extra stock to try to please them.
Now the ones that say 'Do you HAVE this in blue?' really want the blue one and will buy the blue one if you have it. But the ones WONDERING if you make it in blue are not really going buy the blue one...they just want to see it.