It's a con! Why? Because the price is far below what the seller would get from open bidding on eBay. 5DIII bodies at 760 UKP and 5DIII+24-105 at 750 UKP are just not possible.
And for those that say they can get them for this price in Swedish Krona from NL - according to by calculator 3048 euros (the NL price) converts to 25,750 SK or 2,376 UKP. And this 5DIII offered at 750 UKP on Gumtree is equivalent to just 8,128 SK (at the x-rates web site).