And, if you're working at a non-startup and getting $250-$300K, you are very, very lucky. That's far, far outside the realm of what I would consider believable, even in Silicon Valley. I may be a grossly underpaid sucker, but in my 15+ years of experience I've never seen even close to that. Jeez!
How much of that was the base pay? I received a Google offer as well a couple of years ago, with a very concrete salary and a very handwavy "and there are bonuses and stock". Did your offer actually spell out how much the bonuses and stock were worth, or did you only find that out once you accepted the offer?
Haven't accepted yet (deciding between Google and a "hot" late-stage startup). The rough breakdown is $115k salary with 15% bonus if I "meet expectations" (presumably more if I "exceed expectations") + about ~$400k in stock over four years. Add in a sign-on bonus and we reach the $240k average.
If you're working at a startup and getting $125-150k, you're lucky. Many people work at startups for half of that or less, plus those lottery tickets.