Phat Lewts has a transmog list you can import into TSM2 here:
Alternatively you can also do the Great Deals page at The Undermine Journal. Just select your server and faction, mouseover great deals, and select “great deals” to bring up the right page. *Almost* anything with the dot on the far left is undervalued and prime for profitability. Keep in mind the quantities when you are looking at buying something. Someone might not know the value of an item, but it could be you have to buy 25 of them to make it worthwhile. If I have to buy more than one to recover my investment I pass on the great deals.