According to a survey conducted by department store Debenhams, the average wedding guest in the UK spends £510 each time a family member or friend ties the knot.

(The cost of celebrating a wedding as a guest breaks down into the following:-
ITEM                           COST 
Stag / Hen do               £150
Outfit                              £80
Drinks                             £80
Wedding present            £75
Accommodation              £65
Travel                             £60
TOTAL                            £510

And that’s not all, because most Brits will attend 15 weddings in their lifetime, costs can amount to more than £7,500.  Not so much “Here comes the bride” as “Here comes the bill”.)

Source – Net Mums