i really want to join a buying group - have booked flights and hotel (coming from UK) - the flights are non refundable, so will be a long week hanging about if i dont get tickets again this year
I can guarantee that there will be tons of stuff to do outside of the convention center (and those won't require a Comic-Con badge either). Prime examples include Nerdist as well as NerdHQ panels and exhibits at Petco Park. Even if you manage to only get a few days for the convention during the general registration sale, there are many things to see and experience.
For now, don't give up hope just yet!
With that said, information about general registration buying groups will be forthcoming!
Right now, my recommendation is to take this opportunity to get to know your fellow forum members by posting and interacting with others on the forums. By doing this, you'll gain a level of trust with each other that will inevitably help out in these buying groups in the long run. With that trust, you'll know that there are people you can count on for pre-registration or general registration in the future.
(Lurkers and newbies, I'm talking to you! ;p)