…some conditions apply.
Back when I was a wee level 70 hunter, I obtained an Ancient Petrified Leaf from Molten Core and completed the class quest. Then I stuck the items in my bank and thought no more of it.
Fast forward to today. In my endless quest for more bag space on my main, I went to Wowhead’s list of available bags and sorted it by amount of slots. (Verdict: I need to go smack Bronjahm for Papa’s Brand New Bag and two-man Onyxia with Alieth again for the Enlarged Onyxia Hide Backpack, but aside from that, it’s Embersilk Bags until I’m ready to ugrade to 24-slotters.)
While I was looking through the list, the Ancient Sinew Wrapped Lamina caught my eye. It used to be a smallish quiver (18 slots), but got switched to a bag in the Great Ammo Removal of Cataclysm. I knew that. I had, however, assumed that it would into an 18-slot bag.
It didn’t. It’s a 24-slotter. The cheapest widely-available 24-slotter is 3k gold. Needless to say, I’m quite happy.
It is, unfortunately, unavailable post-Cataclysm: the quest items no longer drop. But if you did the quest beforehand and think you might’ve kept it, go check your bank!