Getting a $300K job is like winning the lottery. Quitting such job is like refusing the lottery after having won it.

You should only quit such job if you have gained strong social connections inside the company who will financially support you on your next venture. I often tell people that social networking is everything in tech. Talent is to success in tech what health is to success in the Olympics... It's a base requirement but it doesn't make sense to focus exclusively on it. Once you're in, it's pure social networking.