Hey there,
First off thanks for checking out our project. I'll say that we were very much in the same position about 2 years ago with nScope. We had created something cool, actually made a bunch of them, and we wanted to get it into the hands of more people. I'll try to summarize a few of the lessons we learned during our Kickstarter project in hopes that it helps you.
We vastly underestimated the amount of time it takes to procure parts, especially when you want them to be cheap. We thought 4 weeks was good enough to cover all manufacturing (granted we were expecting volume to be about 250 units), but in reality, it's turning out to be more like 16 weeks. If I were doing this again, I'd plan for a full 6 months between having a working designed PCB and actually starting production. It's probably a bit more than necessary, but better to be ahead than behind.
When it comes to pricing, I'd recommend reading this article.
http://makezine.com/2013/05/22/maker-pro-how-much-should-i-charge/. It's interesting to note that suggestions for retail pricing range from 2.6x to 5x the cost of goods. I'll say that we started this project hoping to sell it for only $50, and after seeing 2.6x we raised our expectation to $70. (Our BOM is much more expensive than the $10 estimated earlier in this thread). And even after the $70 hope, several unexpected costs kept creeping up.
I would be very cautious about trying to produce a board and ship it to customers for $20. My feeling is that would not only take some very lean design, but I think also high volume and partnership with a streamlined logistics provider. That being said, it's obviously possible to produce cheap boards and sell them to customers, Raspberry Pi being a clear example.
At any rate, I hope you do try to get your project out there, and I wish you all the best. Do you have any online documentation or demo of your project?