Factory stores are not like they use to be years ago. They used to sell stuff that didnt sell in their regular stores. Now, majority of them sell straight to outlet clothing. These are generally items of lesser quality than their main stream stores. In some cases the items are made of leftover materials. When outlet stores get clothing from their regular stores it usually goes straight to that stores clearance rack/bin and when you see you know why its there. They are usually some off the wall color, style, far out of season or irregular.
If you patient you will find better deals in the regular store that at the outlets. Last year I found a pair of cargo stantons for $20 that the outlet had $50 and were lesser quality.
Stores I know off the top of my head that sell straight to outlet clothes are:
Saks Off 5th
true religion
banana republic
jcrew
coach
ralph lauren
Majority of the clothes in these stores are made just for outlets. I would say 5% could have been found in regular stores.
If you are suspect you can ask the store SA.
if you do a google search, you will find sites that will second all of this.
http://www.divinecaroline.com/22269/103269-buyer-beware-sneaky-tricks-outlet