Originally Posted by
59Impala
the advantage of upgrading with miles vs outright buying an award ticket is you can earn miles again. Often the Y fare is almost the same price as the taxes/fees on an award flight. Upgrade and award ticket are very similar in mileage, too.(56k vs 50k for NOAM). I think is worth it.
This may make sense if looking to travel in C (buy a cheap Y, upgrade to C via miles and get miles for the trip, as opposed to getting an award in C). If looking to travel in F, the numbers will usually not make sense.