Lufthansa wanted $450,- for an oversized bag (300cm sides, 30kg) on a 3h flight. Awful company.
They did let me prepurchase a pretzel though. (And then never gave it to me on the flight.)
I STILL don't understand the angle there, but I learned you can buy a plane ticket to anywhere in the world (except Australia and NZ), day-of; for about $2500.
Some airlines might not enforce that if you're deemed an important enough customer for them, but I just want to bring this up because being a no-show in the outbound flight and keeping the return flight is not a right that customers have in general, basically in any IATA airline. It's not really Lufthansa specific, those are rules that the whole industry applies.