Yeah, I want a cheap flight, but if there was a small perk where I could physically lie flat for ~15 minutes at some point during the flight, I would pay for that. I haven't been able to really deload my spine for pushing 48 hours (aside from some psuedo-yoga stretching while standing) due to further connections and layovers and it sucks.
International flight is an amazing, painful miracle of science and technology. Maybe SpaceX's BFR will make it better :-) But I highly doubt we'll ever see a reasonably priced long-haul flight with a gym available to us peasants.