Steal non-displays from shops?

My memory is a little weak, but if I recall, both Morrowind and Oblivion the shopkeepers had all their stock stored in their shop. I'm getting to the point where a lot of really nice stuff is being offered for me to buy, but cost 5-7k each. Besides display items and misc others, are the items that change as days/levels pass not stored in the store? Like glass, ebony, robes, ect? Unless it's all stored on their dead bodies (haven't killed the shopkeeps yet), are they all in limbo?

I've tried pickpocketing, but what they have on them is not what their selling. Oh well.