UPDATED: 90minutes later…
… registration is already full!!
unfortunately, there seem to be a problem with the f3xvault website and you cannot pay now that the limit is reached….
I am waiting for a solution, very soon hopefully
you can pay once logged on f3xvault, by typing this address: http://www.f3xvault.com/?action=event&function=event_register&event_id=897