We never added it up, though I remember certain parts eg my dress, the chapel, venue price per head.
We married in 2004 when the wedding industry was only just starting to go bananas. For example, we could choose between traditional old-fashioned posed photography (on film) or the new reportage style (digital). We weren't particularly fussed about photos beyond the traditional set pieces, so went with the man about to retire for £300 rather than the bright young thing for £1200. Similarly we could choose between the local high street florist, or the modern style occasion florist (again, around £400 all in v £2000). We had a Waitrose cake rather than a confectioner's cake, etc, etc.
I think that maybe nowadays it's far harder to find a basic option. A digital photographer has to spend hours going through all the images she shoots, so of course you're going to be spending hundreds if not thousands of pounds for her experienced professional time. There isn't an option for "a hundred shots on film and he has the best twenty printed, after half an hour squinting through a microscope at the negatives".
I also think that the sheer quantity of photos changes people's expectations of how everything has to look. People spend stupid amounts of money on decorations including chair covers and table decorations and bespoke boards and so on, which yes ok make the venue look great in the photos, but which wouldn't be missed if they were absent. A bit like how you can think your house is clean and tidy but if you take a photo of a room you see the half-finished jigsaw and the smeary window. If you are expecting to experience your wedding mainly through photographs after the fact then you need it setting differently.
I'd say an average wedding looks like this at its basis, for 50-100 guests:
bride's outfit - £1000
hired suits - £100 each, so say £500
wedding venue - £250 - £500
reception venue - £2000
catering at £75 a head - £3750 - £7500
disco/band - £500
I make that £8.5k minimum, easily £12k, and for a fairly ordinary wedding without fancy invitations, additional decorations, etc. I haven't included rings or honeymoon as I don't consider them part of the wedding itself IYSWIM, but DTTB does and the survey might have. A big blow-out holiday for two could easily be £5-10k on its own and people might well spend four figures on a wedding ring.
I can't believe that it is the average, unless most are paying £5k and the £1,000,000 do's are throwing off the averages?!
I think that's right, though I'd say there will be a lot of people paying around the £10k mark rather than £5k as standard wedding venue catering will be several thousand on its own.
I know everything can be done cheaper or dearer, but if you're looking at the mainstream shops/venues etc then I think this would be fairly standard. I also think that in my experience weddings tend to be more like 100 people than 50 and as it's the catering that forms a major part of the expense it quickly adds up.
tl;dr: catering for lots of people is expensive unless you DIY. The second you ask a professional kitchen to do a hundred covers, it will start to cost the same as a new fitted domestic kitchen!