I have re-visited this as a possible starter project for our business, and I think it’s a possibility.
I have written it up in a PDF file that you can see/download here: http://jameshardiman.co.uk/JH_files/MinimalArduino.pdf
There’s a rather messy beginning of a costing spreadsheet here:
There are a number of links and videos referred to in the PDF document: I have listed them all here, to make it easier: you can just click, rather than typing in long internet addresses!
The RRRRRRRRRRBBA, a $3 Arduino (Instructables.com)
Arduino Project Board (Instructables.com)
(If we want more than 200, it’s a different process, and we have to e-mail
to get a quote.
Crowdfunder Rewards example
ezine articles (I have never written one, but really ought to!)
Hack-a-day (there are MILLIONS of articles; I thought you might find this fun!)
And I just found this very useful link about bootloaders!
… which refers us to this, which I will need when we get ourselves set up