I understand A/F's complaint to be one of a lowering of dress standards rather than the cost of complying (to the invitation standard) If that is the case, I fully agree. I retired back in the early 80's and have not been to a civvie function which comes within shouting distance of a Summer Ball.
Mind you I did fall foul of "dress standards" many years ago and was asked to leave by the PMC . My crime was to wear stiff white shirt,wing collar and white waist coat (after it was deemed for Royal occasions only) and removing my jacket to drape over the shivering shoulders of my wife - we were in an unheated marquee and the Ball was in Germany in October.
On this occasion I won when the Staish told the pratt of a PMC to back off.