It turns out we're all pretty rubbish when it comes to estimating just how much we should pay for a plane ticket.
People mis-estimate fares by more or less than 50 per cent, or $200 (£129), a survey by flight app Hopper has shown. This means that generally, we have no idea if we're overpaying - or perhaps underpaying - for flights.
Hopper, which conducted the research, says people typically spend two weeks looking for the best deal. But at the end of this period, air fares usually rise about five per cent, and travellers book out of a "sense of frustration with the process."
"We decided to conduct a survey to see if consumers have accurate expectations about the cost of airfare," Hopper said. "It turns out most consumers have no idea how much they should pay."
The below chart shows the amount by which people tend to over-or under-estimate the price of flights.
Its based on a survey of 7,214 respondents in four US regions on how much they'd expect to pay for nine flight destinations - New York, Las Vegas, Florida, California, the Caribbean, Mexico, Hawaii, Europe and Asia.