I would not buy a stand I don't need and don't expect to need for a year or so. Even if it is the best deal now, you cannot know what will be available a year from now. Who knows, maybe the same stand will go on sale for less. And you might decide to go with a TV that won't work with it (say, something with a 60" screen or whatever). And storing things you don't need is often troublesome, as it can get in the way, or cost you storage fees, or it could be damaged while storing it.
But, if you do decide to ignore my advice and buy it anyway, I strongly recommend you do as Exit suggests, as you will not be able to return it over year after buying it if there is a problem with it. Hopefully, it will actually work with whatever TV you will then have, but if it does not, you will just be out of luck.