RE: the price bridging discussion: Assuming the CM does their job right, because this got way more complicated back in February, you should be credited with the PRE-ARRIVAL price of your ticket (AKA the price available online) when upgrading to an AP, not the GATE price.
The difference with tax between pre-arrival and gate is about $21.30 regardless of the number of days on your ticket. (Note: This applies only to 3-10 day tickets.)
The only time tickets are bridged to "gate price" (with the additional $21.30) is to add days or options.