You're thinking about it backwards. Getting investors is super easy, make the perceived reward greater than the perceived risk. That's really all investors care about.
Most people don't know this, but before bustabit was the giant it is now -- there was a time the max bet was like $30 USD. It's better to start small, build up an audience and then if you want to start supporting whales -- it will be extremely easy to find investors after you're proven yourself and the need for more money.
If you want to succeed, you should be instead laser focused on players. What can you offer that the other big reputable sites don't, so that people want to switch to you?
RHavar - I know this is a very subjective question, but as a ballpark figure, how much would a crash site of the same-or-more complexity of current leading sites such as bustabit cost to make? I understand that this is something I would have to bring up to whoever I am paying to make the site, and I have done this already but I want to know your estimation of how much it would cost just so I know whether I am being ripped off or not.
(Anyone else who sees this also feel free to give me an estimated figure if you could, it would be appreciated)
I don't think someone can estimate that for you, what are your priorities to set-up a site?
Domain, hosting, developing the site, depends on the developer that you will get here.
Better if you have dedicated developer here as his job is continuous, it is not just about setting-up your site.
And the price depends on your arrangement with the developer. This plus your initial bankroll.
Maybe you can find someone here to estimate the developer's cost, an actual dev or owner would be your good resources.