I really doubt 80-100k is an average salary... maybe an average starting salary outside of the valley. I had such offers for places outside of the valley as an undergrad (before I had graduated).
I've seen the same for starting salaries in Seattle, over the last four years (graduated in Dec. 06). This is for big companies like Microsoft and Amazon and for some startups depending upon their stage. Anyone 26 and under would see the same.
I'm 24. And to back up what wikyd is saying, this was from one of the large Seattle area companies. Current offers remain in the same range from what I hear.