I followed every step of the Merchant tutorial but still failed to get a merchant to sell anything.

I duplicated the container from a College of Winterhold vendor and replaced that with my own list. I placed it right under the floor of a cell and checked that it had everything I specified with the tcl command. I then created a vendor faction exactly the same way as stated in the tutorial then applied it on a new NPC. Strangely enough, when I got the NPC to trade, its inventory had nothing. I can sell it anything I wanted, but there's nothing to buy.

Are there parameters I am over looking? I did set the location parameter for faction to "near self" with 10000 radius as well as pointing to the right container which is in the same room.

One more thing. Is there anyway to undo changes to quest aliases? I copied and pasted the CWMerchants quest and worked on the copy. Just as I finished making the dialogues, I wiped the aliases in the copy thinking they are just doubles. But when I checked the CWMerchants quest later, I found that its list of aliases were gone, so they presumably were linked with the duplicates (wtf?).