You have to watch the cheap ones on ebay,
There are good ones of these (forget the name of the video processor in them) and bad ones. All from china to make it more difficult.
I spent about £40 getting one of these in from China, from a reputable seller, known to sell the good ones, not cheap fakes.
They are only really worth £40 if you are happy to wait for the import though.
I wasn't recommending the cheap ones on ebay ( I've read a lot of very bad reviews, thats what stopped me from buying one). I meant the opposite, that the Groupon one might be just as bad.