Sorry - the website is here (http://www.odyssey2010.org/), and the membership prices (it's a weird terminology thing - many con-type fans get sniffy if you say "ticket") are under "join". Memberships, unlike hotel rooms, are in infinite supply. Once you have your membership, all the programme items are open, except a few things (I think only the kaffeeklatsches) which have to be signed up for in advance since they're in high demand with very few slots.

Short version: £20-25 for a day, exclusive of food-travel-etc.