Met the majority of these guys but some not at a "convention event"
So vote goes to
Connor Trinneer
Jacqueline Samuda
and the incredibly unlikely Robert Carlisle (more for his role in OUAT than Universe though)
As others have said rule of thumb is £5 difference (either way) for auto compared to autograph. Anything greater would be v v surprising and incredibly disappointing!
20 guests over a full weekend whilst a nice idea in theory will never happen - at least not in the form we know and love for the Chevron events. It is just not possible or plausible from an organisation or monetarial standpoint.