If you had blocc.com, that would perhaps have been worth something, but I'm not sure there will be many takers for these.
blocc.net is definitely the better of the two and the one I'd try and sell. But you're probably only looking at low xxx at best.
theblocc.com I'm doubtful you'd ever sell.
That said, if cryptocurrency does survive the next few years and become something truly big, who knows. That said, even if it does the everyday user probably won't really know or care about the concept of blockchains, in the same way that I don't really care how VISA's backend systems work.