Thanks for hanging in there with me...
IF I figured it out correctly, (and thats a BIG IF), this is what the savings would look like:
Buy a 6 day PH w/ no expire from UTC = 371.95
Turn it in for a credit of WDW cost = 390.86
Use that credit towards a DVC AP = 414.29
414.29 - 390.86 = 23.42 to pay balance for DVC
added to the original cost to UCT 23.42 + 371.95 = 395.38
Ultimate Savings - 414.29- 390.86 = 18.91
Is this correct?
I haven't looked, but just be sure you buy the UT ticket that offers the biggest discount off gate price that doesn't go over the cost of the AP with DVC discount. Remember, UT prices include tax - Disney's do not (when listed on their website).
You do not need to buy a No Expiration option as the ticket's clock (14 days) doesn't start until the ticket is actually used. They're all "no expiration" until used. UT makes it a little easier by giving you the discount off retail in parenthesis (or at least they did last year when I last purchased).