I'm travelling alone. Flight is 10 hours. Adding seats to the (economy cheapest) booking raises the price by about £70 - £85/flight and it's round trip. Economy cheapest means I am allocated a seat randomly - no choice even at check-in. Price without a seat: £425. With seats: £602!
I have a half hour drive on arrival at destination, but a route I know well, and even if I don't sleep at all, timings mean I will be okay to drive. No driving on return.
But... I like an aisle seat. I stand up and move like once/hour. Crawling over people is pretty unpleasant, for everyone involved - though I would do it anyway.
Hmm. Aibu to just hope for the best on allocation?? How bad can it be? £175 seems insane to pay for seats.