If you buy from the site shops though, there's never any chance of losing money. All the quests pay more than each item's ba[injection]se price even at the lowest level, and it only goes up from there. Just stock up before you do your quests, so you won't have to resort to expensive Merchant shops.
I do agree with the first part though, at least if I understand what you're saying right.. I just know it'd be very useful to be able to tell which items you do and don't have for a current quest. I always hate having to spend some of my precious time trying to figure out which item it is that I don't have.