On the first Thursday of every month the SAM (and several other museums) offer free entry to the public.
Given that Thing One and Thing Two are willing to wander through the museum only if we do it quickly,
without lingering by ANY of the things that fascinate me,
I find myself willing to pay the peripheral expenses (parking, food, gas) but not the entry fees in addition to that.
This works out beautifully. On the occasions I can get to the museum solo and take my own sweet time I'm very happy to shell out the bucks for the hours I will spend there but when we will be in and out in about an hour it just kills me to pay for the entrance fee.
The Things are also much more willing to visit knowing that they can just walk though, only pausing by what interests them as briefly as they want, and then move on to eating mini-crack at the Pike Place Market.