I agree with all the above comments: it’s tacky.
I’ve heard of real stories where people from all occasions (even weddings!) try to get the partygoers to pay who are attending. Potlucks or warning everyone in advance they will have to contribute is at least fair warning, but having a cover charge is very tacky. It’s almost like a restaurant. In which case, if we don’t like the food, can we get a refund?
I had a friend who went one step beyond that and held a “crafts party” a few weeks before Halloween. When I arrived, I found out that the crafts were actually us making her Halloween decorations, nothing we could take home.
She even asked me once for my opinion about having a “gardening party”. I innocently enquired if we would each be exchanging plants and seeds, etc., but was floored when she told me it was to clean up her backyard! I guess we were all pitching in without realizing it….free labor