That "average wedding" price figure is artifically high. It's based on the 'reported cost' from frequenters of wedding-planning websites / magazines. Very few Clodfobbles contribute to their dataset. Also, I think it's the mean average, not the median -- so Sean Parker's $5 gazillion dollar wedding nudges the figure up more than it should.
A few months ago I skimmed this article on the subject, so my recollection could be hazy.