I was wondering the same thing, can't find tri-tips anywhere either. Good to know they have brisket at GFS, I was getting ready to drive to Vernon Hills to see what Costco had. I haven't been to GFS since they opened (taste testing day), I thought they only had pre-made foods. I have a Sam's membership and they occasionally have brisket, but only flats, got one of those last year.
Weber Summit S-670, Backyard Bomber MJH, Mini WSM