Slap Chop is about ?10 delivered on Amazon. It does look good but would probably end up at the back of the cupboard gathering dust. I bought a similar device a few years ago and although it worked well, the hassle of cleaning it meant we almost always just used a knife instead. IMO stuff on infomercials always look brilliant but always underwhelm when they arrive.
I'd be interested to hear from anyone who has tried this one though.