AnnaOnTheMoon, please be sure you understand how your friend's 'buddy pass' works and be prepared for that. I'm not saying that it's not a great deal - because it is. I can get 'buddy passes' from my brother, but at least in the instance of my brother's airline (your mileage may vary!), it is a standby ticket. Meaning if there is one or more seats on the plane that have not been sold to the general public shortly before the flight takes off, you get on the flight. If there are no seats available, you don't get on the flight & you wait for the next one (which on international routes, the next flight could be on a subsequent day...and it'll still be a standby ticket for that flight as well & so forth). It's called a 'Non-Revenue Fare' (the buddy pass) and carries the lowest standby priority on the pecking order of who gets a seat on the aircraft.
When I've used my brother's privileges, I've always been successful in getting on because he helped me to select flights that still had plenty of seats available as the schedule got down to the wire. And it's sweet particularly when I've scored a business class seat for the transatlantic leg. But there is always the chance I won't get on the flight at all. (Hubby & I won't use buddy passes if we know we
have to be here or there on a
guaranteed date - like returning to work, or if we have car/hotel reservations that are non-changeable or non-refundable, etc.)
So please be sure to check the terms & conditions of your friend's buddy passes...and prepare yourself accordingly in case you need to be flexible!
ETA: There
may also be a dress code and some behaviour etiquette sort of guidelines you need to follow, when using a buddy pass.