In SF Bay area, my experience in the last year or so has been that salary comp is pretty much the same between start-ups and big companies, the only exception being super-early-stage startups (i.e. pre-series A) where they really don't have the money yet. The difference is that at bigco, they add bonus and equity grant that have real value, while at startup, they add some % of equity with unknown value. Companies like Amazon and Netflix are also different because they adjust the base salary up to compensate for their different equity award policies.