Big weddings cost lots of money, but also MAKE lots of money... there's a reason behind it all. However, if you don't have the seed money to make it all happen in the beginning, then forget it. Look at things realistically, and create a heirarchy of who should be pleased first. For starters, you and your fiance first, then parents of both sides, then siblings/family... That's a good way to start in my opinion.
Sources: Us Croatians always have 400-500+ people weddings, crazy shit... F'n 6+ weddings a year man lol