How about you sit on the $320 worth of BTC for 2,5 years. After then you'll be able to afford the flight.
If bitcoin continues to rise and doesn't crash yeah, but unfortunately I myself don't think it'll rise that high. BTC would need to reach $126/BTC for that. I got bored of bitcoin when it crashed down to $3 back in 2011, it bugs me to this day lol. Should have bought a lot....