I think you make the assumption that the tech you are creating here is inexpensive. If you can make your idea with $5k and a few months time, go for it. Make up prices and make up numbers.
What if your new product, that has never been done before, will costs tens of millions? Surely those products have existed, and yet are still somehow able to do the prudent 'guesswork' to convince venture capitalists.
What if your new product, that has never been done before, will costs tens of millions?
Bluntly, my opinion here would be that this isn't a viable option for a startup, unless they have access to easy angel capital or can self fund to that amount.
Developing an idea with that price tag is an is a risk orders of magnitudes higher than a low cost startup. Having a hit is hard enough, but you'd need a run-away smashing super hit to even break even.
Even if you choose that path, there are still aspects of the idea that can be harnessed and build at much lower costs to begin income generation to help fund the remainder of the idea.
Investing money of that amount into an idea that has yet to prove itself is not my idea of a good move, really.
EDIT - Curious, what problem space are you thinking about/working in that requires that level of funding?
I'm not particularly working in that type of space, but we are generalizing here.
If you look into startups in the medical, pharmaceutical, chemical and energy fields, you will see very high startup costs while sharing the high risk attached to software startups.
Even in software though, there are companies working on solving difficult problems that would require the work of scientists, engineers and administrators for 1-2 years. This would place you into that multi-million dollar category pretty quickly.
What if your new product, that has never been done before, will costs tens of millions? Surely those products have existed, and yet are still somehow able to do the prudent 'guesswork' to convince venture capitalists.