Originally Posted by
MSPeconomist
BTW, do you mean LIM-ATL-DTW for the return? Or do you have a multicity ticket with a second visit to Argentina?
Check what it would cost to upfare the ticket (pay the official price difference) by doing a dummy booking in D1. Sometimes this is less than the upgrade offer you see on the app. Keep checking and move immediately when you see an offer you like; don't wait for a better price which may or may not appear later. IME the upgrade offers on the app don't appear until at least 48 hours after ticket purchase (beyond the free refund period for most fares) and then come and go almost randomly until the premium cabin is full.
If you and your tickets are eligible for pay-with-miles, you can use DL miles at approximately one cent per mile to pay for upgrades rather than paying with money.
Oops -that was a typo, yes we're flying back to Detroit! Stopping in Macchu Picchu on the way home, bought a flight from EZE-LIM-CUZ from another airline.
I will keep obsessively checking for upgrades haha. If no one buys them, do they just keep DO empty?
The nice thing is, I did a "Modify Flight" thing last night and got $200 credit back for my flight. So that was great!