eBay?
I do have one I could sell, but its probably not worth it even just for postage cost to spain; the front is slightly bent (from where I wedged a CD-Rom in there), the plastic has yellowed (alas most A4000 cases seem to suffer from this), and some of the power connectors have been cut off (and transplanted to my Power Tower 4000; it didn't have enough).
Why do you want one, btw?