To value a start-up company at over 5 million USD? I shouldn't even have to answer that question. So a company that isn't making any money is now worth over 5 million. How long, if at all, do you think it will take for your stake to be worth anything? For it to double, the company, once it goes live, would have to make 5 million on top of that, and that's assuming 100% of their earnings will go into the value of Ether, which it certainly won't.
Just think about it and you'll see how overly-inflated the evaluation is.
When you consider its potential, $5m is pennies. A tiny figure. $5m is nothing these days anyway. We're talking about a global platform here. Banks do billions worth of business on a daily basis. If you're building something that requires a huge amount of talent and time, millions are required. Simple as that.