I am flying ORD to CUN (3.5 hours) and am currently in Economy Plus, since that was all that was available when I booked the flight. So, I had to pay about $39 (each seat) above the price on united.com to book the flight. That I don't mind.

I see that first class is pretty empty for this flight at the moment. To upgrade there, it would be $225 each. So, the difference to first class from what I am already paying 'extra' is $372.

For a flight of that length, is it worth it? Will I get the increased award mile earnings since I upgraded, or will it stick to the original booked class? The flight is currently booked as class E.

Sorry for the questions, all of this is new to me. I barely flew before this year, and now I seem to be going places.