Don't buy it - there's a reason it's only £16.99 - it's rubbish. I bought one a couple of years ago for around £20.00 plus P&P and I rarely, if ever, use it. It doesn't have different temperatures - it's pretty much on (full power) or off (any of the lower powers). When they show the shots from above and you can see the water boiling in a circle - well, that's pretty much where it cooks, or should I say burns if you don't stir stuff enough. I do very, very occasionally dig it out to make a sort of stir fry thing where I bung in anything that's hanging around in the fridge and it does come out quite nice if I stir it often enough and I do like the big cooking surface. It's not quite bad enough to be ditched, but it's not good enough to have a permanent place in my kitchen. It tends to live on a shelf in the spare room.
I think I may have used it once for a full cooked breakfast for DH and myself and it was quite good for that because I could move things that were cooked away from the "cooking circle" and they stayed warm whilst I added other items. In a caravan or any other tiny cooking space it might be very useful but in a normal fully equipped kitchen I'd save my money.
Julie