Some people have destination weddings because they know that a lot of people won't come (can't afford the travel, or can't get off work, etc) so it's a way to extend an invite and make people feel good without them actually coming. So you can end up with a very small wedding, which is still much cheaper than having a huge wedding in a venue in the US. Wedding cost is almost always per guest.

I've also heard of other couples who chose to forgo the big wedding and the bride's father just gave them the cash instead, which they used for a down payment on a house. Almost anyone would agree that's a much better use of the money.