The other thing to keep in mind is that the Stars and Stripes cannot be upgraded or added to and final sale from SOG. It should match your length of stay at either SOG or a Disney resort. Also, the military salute tickets cannot be upgraded or added to either, but you can use 2, back to back, getting you 8 days. Bad thing is, you
MDE will only recognize one salute ticket at a time. So no early fast passes for the second salute ticket used.
If you want to upgrade to an AP, then check out ITT offices and SOG for regular tickets. If you buy from them, you do not pay sakes tax, so that is some savings. Also, check undercovertourist or other authorized ticket resellers. Be aware of tax and shipping fees.
UT has it's tickets price inclusive of tax, and free domestic shipping. Disney will bridge your discount ticket, so when you upgrade in the park, you get the current ticket value of what your discounted ticket is. Be aware, and do the math when you upgrade, to be sure you are paying the right amount to upgrade to the AP you want.
I am all about saving. The other thing is, if you really want free dining, you can save the minimum of day ticket, by not using them, then ask for them to be given to you unused, and buy the ticket you want. That is what AP holders do, they save the required tickets to be at another time, sell them, or I think, some have used them when renewing their AP, to save some money, as they will get the current value of those tickets.