This is an interesting idea. Kind of like how you can buy a thousand bars of ice cream for less money if you buy them all at one time, because like srsly who's gonna do that.
The thing is though, what happens to the people who have already bought a texture on their own? Maybe if it was set up to only the one standard clan texture...but then members couldn't use the ones they'd already bought.
Also, if I'm not mistaken, somebody had suggested this on IRC not too long ago.