I think it cost me £29.99 a couple of years ago. I only actually used it a couple of times but it was good for toast and heating pies/pizzas and things. I also used it for heating tinned peas/beans in a foil dish so no need for a hob. It would have cooked things had I wanted to but the local chippy always proved too tempting.
They do get hot on the outside though so place them on a heat resistant table and well away from the tent wall.
I bought a mini oven with a single hob on the top so that we could ditch the gas burners and gas bottle! It was bought off Ebay for £15. It is discontinued now but I cooked mini roast potatoes, garlic bread and made toast on its first outing. It is a bit heavy but we have a trailer so not worrying too much on that front!
------------- August 2013 - Kingsbridge, Devon
April 2014 - Ladram Bay,Devon
May 2014 - Whitehill Country Park, Paignton
July 2014 - Rivendale, Derbyshire
Try to keep an eye out for either Lidl or Aldi ones. Either are great, heat up quickly, cook well, easy to keep clean and small enough not to take up too much space. Had ours for several yrs and taken allover UK and France! We were easily able to pick up another small baking try so we could cook for family of 4.