Everyone has a different idea about what is worth the entrance fee, and the expenses to put on a show do vary from community to community. I think it is wise for a guild to have an entrance fee that is estimated to meet most of the expenses and hold other fundraisers at the show to help meet a possible shortfall or make a profit. For instance, there is frequently a raffle for a guild quilt or a "boutique" where quilted items are sold for a commission or all profit. Attendees can choose whether or not they want to participate in those.
Quilt shows (and guilds) are a benefit to the community, and it is heartwarming to see support from local businesses and attendees.
I know one thing -- there is a tremendous amount of volunteer work by guild members to put one on, and I would hate to think about situations where they lost money on the venture.
Dayle