Thanks, all. Very much appreciated, @chugh43, @malem, and @harveyhaddixfan.
Sounds like my best bet is to maybe buy 1 all inclusive pass to get the souvenir cup and photo pass, and then do regular tickets, Fast Lane plus, and dining plans for the other two people. It works out to be slightly cheaper that way. Paying for 3 all inclusive when we only need one parking pass seems unnecessary.
Does Fast Lane plus ever sell out? I am a little nervous to drop $500+ a few weeks out, knowing that we're traveling and could be impacted by weather. Is it safe to wait to buy all of this stuff until a couple days before? Or - does the price go up closer to the date?