Another suggestion would be flexible with your itinerary. Let's say you had planned on visiting parks A-G in that order, But park F offers a pass which is good at all 7 parks for $40, and at park A it is $125. If these were seperate and distinct trips it would make sense to hit Park F, first.
If they are all tied into one trip it may not be as easy, particularly if the cheap passes are at a middle of the trip park. I know I have more than once rearanged a whole trip schedule based on some cost savings idea. In your case, if there is anyway to make SFO or SFDL your starting point, it could serve you well. If not then you will have to weigh the SP price differnce vs. how much time/energy/money it would take to get the cheaper pass.
Some parks are benevolent, and will offer to process passes early. For example I am going to SFMM in a couple months, and the price of a SFKK pass is less than a SFMM 1 day ticket, but alas SFKK won't be open yet. Upon calling the park, I learned that there will be processing times available starting Feb 26. (I hear Rideman gasping for air "You called SFKK and are relying on the information they gave")
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David Bowers
Mayor, Coasterville