If you were going to put 300 btc into it, why wouldn't you just develop your own.

It's just a concept at this point. No extensive development.

And you know that people are going to demand a finished product asap which means no real time to test bugs and exploits.

 Ask how many times already established sites like primedice and bit dice have had to patch things up. Hell, primedice  (the site that everyone seems to say is the most reputable) got taken for a million dollars after being around and continually developing for a few years. 

How do you guys plan on competing with pied piper?