Travelers have found it’s best to book a flight 31 days in advance to save up to 2% compared to booking the same week of travel. As your travel date approaches, the cost of this flight route may potentially increase. While opting to book 31 days out may not be an option for all, there are still additional ways to secure a deal in the near future. You might find a flight from St Augustine to Paris 1-2 weeks in advance for as low as $529, or $529 for flights within the next 24 hours.