So - have been invited to a v. glam black tie wedding. Presumably that means long. If knee length, have various options, but my sense is proper girly GOWN is what is required. Where on earth am I going to find such a thing without spending 4+figures?
When I went to a black tie wedding recently, I wore a dress quite like this one, just it had extra sparkles around the waist. It definitely wasn't out of place, there was a mix of women in long and cocktail dresses. I just put some bold jewellery with it.