I'll go along the same line as Intruder. I purchased my house in a rising market (10 years ago). With hindsight, you could have said that I under-bought, as I may have been able to purchase a larger house and would have had a greater value of equity now. But I can tell you I was able to purchase insurance, finance a pension, buy nappies, go on holiday, furnish the house etc. all without the nagging doubt that if I was ill or suffered an injury I would still be able to afford my mortgage.
Declare the flight pay by all means, but don't rely on it.
PM