No amount of money will help you make the decision. The size of your network or having Mark Zuckerberg's personal phone number won't make you become less fearful of failure. And past experience (success or failure) won't be the determining factor in whether you'll succeed in future.
Ever since the rumours about the Yahoo-Tumblr acquisition running over the weekend (which it turns out weren't just rumours), I've wanted to communicate my opinion on the matter.
As an entrepreneur, build your soft assets and continuously improve your skills; build a great team, build a great product, don't waste money and have reserve kitty in your bank account.
My brain has been wired in such a way that I can easily compute the risk & reward of any decision. My personality is such that I chase after the impossible and (when it comes to business at least) I'm fearless in that pursuit.
Most markets that you can enter right now, are already quite saturated and you're likely to face existing competition. Due to the very low barrier to entry to build a new SaaS/web /mobile app, you'll also find that the competition's offering is mostly the same as your solution.