请教一下用UA 里程upgrade国际航班和用GPU的比较

去程是一段1.5hr的domestic，然后从东海岸飞中国，回程是中国到美西，然后coast
to coast的domestic，现在登陆进去发现去程30000mile+600刀可以放在upgrade的
waitinglist上，回程只要20000mile。

两个问题：
1. 去程upgrade贵那么多是因为国际段长点吗？还是跟机票fareclass有关（去是S舱，回是Y舱）
2. 如果20000mile能升级回程，和用300块买个gpu比那个划算？20000mile如果只是换
经济舱，大概也就200块的value？

多谢

1) Yes, it depends on the fare class.

2) If you buy GPU and not upgraded, you won't get your money back. However, you would be able to get the 20k miles back from United.

为啥拿不回来？

【 在 expressbus (星吧咖啡) 的大作中提到: 】
: 1) Yes, it depends on the fare class.
: 2) If you buy GPU and not upgraded, you won't get your money back. However,
: you would be able to get the 20k miles back from United.