Depends on the venue how much the admission is - how much it cost for rental of the location drives the price. The most I've paid here in the Los Angeles area is $6 but the free cat food and give-aways make up for the admission price.

Some of the shows here have 300 to 400 cats on show from the best of a breed to ordinary house cats. We took a European guest to one of the shows and she was amazed at how many breeds there were and how different they were from each other. It's a great experience.