Here's one of the DIS threads from last year about it. Costs vary, depending upon whether you just want the vendor floor or to also add classes (each class costs $ and the prices differ widely). Also, whether or not you stay overnight (then again whether you're at the conference hotel or another one in the area...) Then, whether or not you crop - fees for that, too.
So, it's not easy to answer your question about the price! You can do a little or a lot! And pay accordingly...
http://www.disboards.com/showthread.php?t=2162470&highlight=CKC+Manchester
We (the Boston Scrap Mafia) went last year for the first time and enjoyed ourselves. So, we're going back! Here's the link for the 2010 shows across the country.
http://www.scrapandpapercorner.com/events/ckc/index.html?refer=1