I believe it's net worth of a million dollars (http://www.investor.gov/news-alerts/investor-bulletins/inves...). I've been following the crowdfunding legislation and it seems like there may be additional requirements to accept such investments if you are an early startup with just friends & family investments.
But the bottom line, I think, is that to do the strategy you suggest, you currently need to be an accredited investor if the startup is not already setup for crowdfunding.
Thanks to a new law, though, you no longer have to be accredited to invest small amounts.