Planning out way ahead on this one, but we're headed to BKK from LAX in November on Evergreen Deluxe on EVA. Did the same route/class last year and when we arrived at LAX (and also when we left BKK to come back) EVA advertised on-site day-of upgrades from (presumably) coach and Evergreen to Business Class.

Has anyone done this before? For the life of me, I cannot remember how much they were advertising the upgrade for at LAX...I remember something in the $300/$400/$500 range.

Obviously, I know these upgrades are subject to availibility and are not guaranteed...but will definitely seize the opportunity should it arise this year. We'll be booking our tickets in Evergreen so wondering if anyone has paid a same-day upgrade to Business on that route and what it roughly cost.

Thanks for your help in advance!