Snap me out of this if IABU
Friend is having fancy dress party for their birthday, no theme 'it'd just be fun for everyone to come in fancy dress'.
Why does fancy dress enhance a party? It's costing me £100, to do costumes for my family, that's a £100 less to spend on food present.
I just see it as an inconvenience, and not adding anything to the party.
AIBU - fancy dress does not add value to a party?