Ticket days
Start with the exact number of park days you already plan to use. Do not count a theoretical return trip unless it is genuinely likely.
Annual Pass
Do the pass math before you talk yourself into perks.
A pass can be smart if the ticket days, hotel discount, parking, and return-trip odds line up. Otherwise it is a very expensive souvenir.
Hotel discount
Passholder hotel rates can be meaningful, but they are inventory-dependent. Compare the AP quote against the standard quote for your dates.
Parking and food
Parking, food, and merch discounts can help, but they should not carry the decision by themselves.
Blockouts
A cheaper pass with blockout dates can be the wrong pass if it blocks the dates you actually travel.