Question about AMEX travel credit: I purchased economy plus seats on my EWR-SXM. The buy-up cost was $114 per seat (2 of us traveling). The upgrade cost to F class at the time was ranging $489-608 pp. AMEX Platinum refunded my seat cost (up to the $200 annual credit). Now after purchasing Y+ the buy-up cost to F has fallen to $286. When I click on "price breakdown" (for the upgrade to F) on the united website, it shows this:
United Business® $400.00
Previous seat -$113.99
Price difference $286.01
So my question is ff we buy-up to F, would we get refunded the original Y+ purchase (and therefore lose out on the AMEX Platinum credit), or would this be a completely new charge and I am just paying the difference ($286) out of pocket? I would be more likely to upgrade to F if I do not have to pay the full $400 pp and can still take advantage of the AMEX credit that I effectively already used.