It's possible to get a flight on an Airbus A380 for less than two hundred quid. You'll typically exceed 550mph, and possibly exceed 600mph, depending on the flight you're on - they're capable of over 670.
Should have been on this Norwegian flight, with a tailwind topped out at 776mph!
www.dailymail.co.uk/news/article-5289883/Norwegian-breaks-record-fastest-transatlantic-flight.html