According to the U.S. Travel Insurance Association, you'll typically need to pay between 4 percent to 8 percent of the total cost of your overall trip. It all depends on the type and extent of coverage, the length of your trip, where you're going and even your age. Experts say it's worth it to shell out the extra bucks regardless of your flight status. The credit card you use to book your trip matters too. Some credit card companies offer insurance deals that can make your trip a little cheaper.