We skied Snowbasin last season for five days midweek. We did the math and found it was cheaper to buy reduced, multi-day midweek tickets in advance from the resort than purchase the Ikon Base. Of course, with the Ikon Base, you can ski elsewhere as well.For passes your least expensive (not cheap) option is the Ikon Base Plus pass, currently running $1200 I think. Of course, that covers a lot more than a week at Sun Valley. Or you can get the Mountain Collective pass, although I don't know how the math would work on that one if you don't buy it early and choose the 3rd "free" day as Sun Valley.