I would take that with a grain of salt. That domain was registered 1 week before that 'auction' and hasn't been sold since...so I don't know how legit that sale price is. Even if that was a true sale, which I'm skeptical of, Pizza Pizza is both the slogan for a major pizza chain and is also the name of a number of pizzerias...so it's a little different than Water Water.
Here in Serbia we have a bottled water called "vodavoda" which means "waterwater". They were one of the sponsors of the Basketball World Championship 2006 in Japan.
It is always presented as "vodavoda" which is bad news. But "You Never Know…Until You Give it a Go".