$50 seemed a bit steep to me as well but having not "done" a Burns night before I have no frame of reference.
$50 is actually fairly reasonable when you consider all that goes into a Burns Supper; Haggis, the venue, decorations, entertainment, etc. Our local St. Andrew's Society charges $40 per person, whilst a Burns Supper in a major city like St. Louis or Chicago can go anywhere from $70 to $100 per person.

That's not to say that a Burns Supper cannot be held for less cost, but as the organiser of a Burns Supper for over a decade, I feel that some explanation is owed when people question the costs.

T.