I’ve no idea if this works with your schedule or not, but the cost of a seasonal pass - block outs apply at Christmas/New Year, spring break, and the month of July - is ten dollars more than a 3 day park-to-park ticket. With that, you can often book on site hotel for a huge discount, especially on weekdays.
This is what I did when I had to add two nights to my trip due to airline schedules.
Bought the seasonal AP for $285 vs $275 for a 3 day PtP ticket. Booked two nights at Royal Pacific for $175 each (regular $299). With that I got the Express Pass free, regular $90 per day, or $270 for three days. Added benefit was going through security at the resort, and taking the boat over to the park gates - instead of the mob scene and stampede at City Walk.
So, for $635 (plus tax) I enjoyed what could have cost $545 for just tickets and EP, plus I got two nights in an awesome hotel on site for that additional $90. Truly a bargain!
I was by myself, but if DH had been along on that trip, the value of the free Express pass would have doubled.