Hi Erfola,
I’m not a patent attorney but I’ve seen a few people develop products. If you’ve dealt with professional venture capitalists, then they should keep their mouths shut and not tell others about your idea. I don’t know who they are but their level of professionalism is for you to decide. If they keep their mouths shut, then who is to know that they know anything? If they are professional venture capitalist you should be okay. Still take an NDA with you when you meet.
I consulted with one of my team who studied Entrepreneurship and Innovation at the AGSE. He said you should only meet with venture capitalists when you know exactly what you want from them. You need to be able to explain what it is that you want, how your idea will help people, and exactly what it will be used for. However, since they seem interested already, go for it. Just try to work out what you need from them so you have something to go by.
As for costs:
To get an accurate cost of production you’ll need to get some proper drawings and submit them for quotation. Remember when you are requesting for quotations you can ask for different numbers of production to get an idea of economies of scale.
I am interested in hearing how things pan out. If you get the chance let know.
Good luck with your idea!
Regards
Sarah
Documentation and Quality Control Engineer
http://www.getyourstuffmadeinchina.com