If you have ever attended a wedding, you would know that how much it becomes expensive to go to one. If you are alone, you maybe even afford some tuxedo or a suit which you have not worn for a while to get it dry cleaned and wears it to the function. But if you have a family with kids you would know that the expense can run into hundreds with new clothes for the spouse and kids, gifts and then reaching to the place of the wedding.
You can easily get away with not attending if the wedding clashes with your other activities or the couple are not that close with you but if it happens to be your family or your best friend then there is no choice you have to attend. Locally you can manage with just going there by your car and getting a gift. But if it is in another city and you have to fly in there, then the cost of attending the wedding with your family can easily run into thousands with the airfare and hotel accommodation, clothing, cab fare and gift buying. In this economy if the wedding is in your family then you don’t have much choice but if not then you can always skip and just send them a gift with apologies enclosed and it would be understandable.