richarduk: You're obviously not Google or Facebook calibre or we wouldn't be having this conversation with you. 2nd, the companies you work for, the actual product you develop, and the city you live in will be a huge factor, and if you possessed a shred of genius to go with that 20 years of experience, nobody would have to tell you that.
Back on topic, I'm shocked that the average for those companies is only $120-something-k a year. I already make that about that much, my plans were to eventually wind up at Google someday making $200k/yr. They only take the very best of the best, who I assumed all make way more than $120k/yr. I actually was recruited by them when I was a relative n00b, and basically petered out at step 3 (out of 8 or 10?) of the Google interview process, predictably so considering I was relatively inexperienced, have never written a book about Linux or Python, and don't have an Ivy League education...