Yup, parking in downtown seattle is definitely pricey. You mentioned having to go somewhere on Sunday, however. It should be noted that, on Sundays and holidays, parking downtown is free. As well, there is often street parking that is free in the evening (after 8pm, maybe? Can't remember...) One of the things I do is actually stay out of downtown until the evening, and then park on the street. If the next day is a weekday/saturday, you'll have to move your car or pay for parking before 7am, which works for me, because I'm usually up by that hour. Or, if the next day is a Sunday, then you don't have to worry about it at all. Hope this helps!