What exactly are you disagreeing with me about?
Conventions that have actors in it get quite pricey because they’re quite pricey. Your primary cast members are going to cost in the high thousands of dollars. Like I said, 7K+ And that’s for one cast member. The smaller known name of the actor, the cheaper they are. but, they still cost money (and that money also includes the fee for either their agent or convention agent/handler). Then you have to pay them per diem. Their hotel. Their transportation (usually first class plane or ground transportation). They can make you back your money with the autograph sessions and photographs but that money comes in after the fact when you need to pay them up front. I know we would all love to think they do this stuff for free out of love for the show like we love it but it is their job.
But, if one can get guests for free or by just paying transportation/per diem and forego actual paying them, then great!
Even a small time convention costs quite a bit of money due to venue. Venues aren’t cheap. Of course, the smaller your convention is the smaller the budget needs to be. But even having a venue for a day or three will costs in the thousands.
Unless you’re going super small convention with a bunch of fans hanging out then it’s just a fan meetup.
If anyone wants to do a type of convention, honestly, I would suggest with fan meet ups. Do local fan meet ups. Try to organize with other locations where it all happens around the same time. Keep it building. Then try and merge these meet ups and invite low profile names. Some of the lower tier writers, any make up crew or costuming, etc etc. And build up from there.
But, if anyone is thinking of doing a convention where Lana Parrilla shows up then just be prepared to spend a lot, lot, lot of money.