Okay, so, spelling this all out even more, for my benefit and to get verification that I'm looking at this correctly, lol. Buying a 6-Day Park Hopper® + Water Park Fun & More - No Expiration at UCT would cost $577.47. Buying this ticket with tax thru Disney would cost $577.47 + 72.00 = $649.47. And, if I buy the ticket at UCT, and then enter my first park on arrival day, the ticket's value will then be $649.47, just as if I'd bought that ticket thru Disney originally. Then, I can go to GS and ask to upgrade and bridge that ticket to a regular AP. If they bridge it correctly, it should cost me the difference between the value of the 6 day tickets that is now $649.47 and the Disney regular AP cost of $675.21. So, I'd pay an additional $25.74 at the GS counter,(if they quote me any other amount, we'll ask for manager or stop the upgrade and move to another GS). Making my total payout for the regular AP $577.47 + $25.74 = $603.21, saving $72.00!! I definitely like seeing it all spelling out like that, lol!
TIA!