That changes the negotiating perspective of the job seeker. If you're surrounded by a rather large number of companies in that range - http://graphics.wsj.com/billion-dollar-club/ - and are skillful enough to enjoy offers from multiple suitors, you're bound to do your analysis, perhaps employing some backchannel communication.

If the theoretical maximum of company exit is in single millions, then spending time negotiating 0.25% vs 0.3% equity package is meaningless.