I finding this thread to be somewhat confusing.
The Arduino platform is a microcontroller + a boot loader and that's it. Please correct me if I'm wrong as I've never used one. The discussions in the Pro-Arduino camp in this thread seem to conceded that an Arduino Uno in a 'professional' project is a little amateur hour BUT an Arduino Nano is more professional because it allows you to directly solder it to another board or because it's small or because it is missing all the peripheral connectors that may be unused?
Well lets look at the Nano then... Current list price US$22. And yes lets ignore the cheaper clones because we're making a 'professional' product here and not one sourced from questionable gray market supply lines.
What do the components cost?
- Microcontroller (ATMEGA168-20AU) = $3.42
- USB Serial UART (FT232RL - 895"FT232RL) = $4.50
- +5VDC regulator (UA78M05CDCYRG3) = $0.62
- 16 MHz christal (ABL-16.000MHZ-B2) = $0.34
- Mini-B socket (67503-1020) = $0.65
- About 10 passives. Lets say your getting ripped off for the passives like everyone else at the moment and pay $0.13 each.
So your total component cost here is $10.83
If you can get a PCB made for $5 !! then you have just saved $6.17 per unit. And those prices above are for single units. { Actual part.no and sources -
https://www.arduino.cc/en/uploads/Main/ArduinoNanoManual23.pdf }
Point is, you would be better of designing that stuff in to your own PCB and if your product requires more components then those listed above then you have saved the need for a PCB and separate Arduino board.
My other reason why this all does not make sense is that for any product to be sold in any country requires some type of regulatory approvals be it CE or FCC. The minimum would be radio emissions & immunity and trust me, because I've done it several times now, you don't get much change from $10k once all is said and done. That many zeros just for a bit of paper that no one is ever going to read does sharpen your mind on the dollar and cent savings I listed above.
It also makes me a little mad when people bodge a product together without any approvals and think it's all so easy. They are the ones who look at a real professionally engineered product and say 'WOW what a rip off I can make that for a 10th of the price and sell it'. But that's a rant for another time.