My monthly payment is $145.75 (I just looked), so I guess for 2, it would be about $300 per month. You can always set it up for monthly payments and then when you have some extra money, stop by the booths and pay one off. My pass renews early September, and I would have liked to pay it off early, but thinking that is not happening this year. At least, it is 0% interest so not paying extra to pay monthly.
I go for a lot of the holidays (or on those weekends) - went last Saturday, love 4th of July (special flag retreat), Labor Day, Memorial Day. I have also been on Christmas and Easter before too, but those always depend on the holiday plans with family. LOL