I've got some flights booked to Australia in a few weeks with Emirates. Have just been looking at my booking and there is a charge of £20 per flight to pre book my seats (so £80 in total). I'm flying on my own so I don't need to book seats next to someone but I do like an aisle seat. Would you risk leaving it till 48 hours before the flight (when I can reserve for free) or do you think all that will be left by then will be middle seats?