Can I leave our convention costume group for the panel I bought a badge to attend?

The photographer's new message said 1:30. The animation panel runs from 1:00 to 2:00, and the director I want to hear is only appearing that afternoon. My friend replied, 'We're a set of five characters. The photo won't work with four.'

We've spent three weekends making costumes for a small fan convention. I joined after saying the director's panel was my main reason for buying the $45 badge. At that point, the group photo was planned for 11:00. The photographer has now moved it, and the others can make the new time.

The panel and photo locations are far enough apart that I can't sensibly do both. I offered to take an informal group photo before lunch and wear the costume again another day. My friend said the paid photo session was what everyone had been working toward. I realised it was for her, even though I'd thought the sewing days and being there together were the shared part.

I've already contributed my agreed share of the photographer's fee. Is keeping that contribution enough if I miss the shoot, or did joining the costume group create a commitment that outweighs the panel I mentioned at the start?

The event, timetable and prices are illustrative.