As other posters have said, it varies significantly depending on
how you plan to "upgrade" your ticket. Sticker-type upsells almost never take your current fare paid
or booking class into account, a mileage-based upgrade on UA uses only booking class, and a ticket change would use only the coupon value. If you fly SQ metal, the questions largely apply to SQ upgrade paths which are unique per-airline except for changing the ticket.
Originally Posted by
jsloan
There’s no justification for spending nearly twice as much to fly UA — and I say that as someone who hates the SQ business class seat on that route.
Malicious compliance is certainly
a justification - not saying it's necessarily a
good one
. But as someone with long-standing beefs about corporate travel policies, I can at least be sympathetic to the idea.