What benefit is the UK deriving from membership of the EU's Single Market?

We were already in the Common Market when the EU was formed, so had invested quite a lot of money already. When the EU came along we joined by default as our Prime Minister at the time was a moron and fancied himself a player in the Europe scene. As luck would have it the British Public told Blair they did not want to be in the Euro and from that point on there has been damage control for being part of it. I see what you are saying, but if you have a look at the europa website you will see there is some good to it for us Britt's. A few new theatres and some tourist attraction being cleaned up.