I googled this but couldn't find a clear up-to-date answer. Do I need the normal tier shoulder/helmet in order to purchase the heroic ones with the token? Apparently this was changed at some point in Cataclysm so I thought I better ask.
I have non-tier shoulders and my guild is already doing heroic modes, so the chances of me getting a normal-mode tier token are small.
You don't need the normal mode piece to buy shoulders or head. You do need the normal mode piece, as well as the token, to buy the legs, gloves and chest.
You don't need the normal tier piece for shoulders/helm to get the heroic ones for firelands, but you need the normal piece for chest/gloves/legs. Not sure about T11 content though.