Wedding Fairs???

I was just wondering if many people have done Wedding Fairs? Is it worth doing it? do you get business from it? ….
I have never done one and I have been trying to see any reviews however there are non or can’t find them… and some of them cost £50 a table and others £175?…
Really not too sure which one to go for, I will be doing one for sure and when I do one I will let you know, how it went act. But for now, can anyone help with information and what is your experience ?
Thank you so much for your help ;)
Beata ;)