Please could someone from the UK give me a lot of information about Conventions, particularly in Birmingham?

I just want to know the basic info I can’t find on the rogueevents.com website: I’m not entirely sure what each package contains. If I get an Autograph Package, it says I get prints and autographs from every person attending, and it’s £80; does that mean I can turn up on any of the three days the convention goes on for, or all of them, or do I ask for a certain day out the 3 or what? :S
Also, if guests don’t say they are only there on specific days (e.g. only Sunday), is it right to think that they are going to be there the full three days?
Just curiously, is there any merchandise to buy there as well, like t-shirts and stuff? Because that would rock even more lol!
It also says that I would need to convert the Pound £s to Euros using this site, and I was wondering if anyone has done this and found it good and reliable.
I’ve always desperately wanted to go to one, and now I might be able to, but it’s just the website’s a little vague about all the info and terms and stuff. Any information about past or future experiences – literally, any – is MUCH appreciated! Thanks! =D