There is a franchise called I Sold It, cost £70,000 and you have to find a suitable shop front & finance that yourself too. Doesn't look like this is one of them, but has the same ethos.
iSold It - The easy way to sell online
I had a look into it a few weeks ago, but is much too steep with the charges and commission which are passed on to the customer. They also say that the item must sell for at least £30 or they won't take it!
I sell for other people on Ebay who don't know how to use it or can't be bothered and I only take 10% of the final value price on items under £100. I suppose this shop would be ok dealing with large items or breakables as it's on their heads, but I'll stick with the smaller stuff!