No one expect a $300 PnP machine. Heck, you can't even get a half decent 3D printer for that. You can argue it's pointless to even try and meet a price point, better to focus on getting a solution that is robust and works. And then it costs what it costs.
When I designed FirePick 1, the predecessor to FirePick Delta, my replicable cost goal was $500. This is not end user cost unless the end user is a maker. I adhered to a very strict protocol of multiple, repeatable sources and completely avoided eBay 1-of-a-kind-fire-sales for the simple reason that bragging that I made a cheap machine was irrelevant if nobody else could build the machine. So I tried as hard as I could to make FirePick 1 cost $500.
And I failed.
FirePick 1 cost ended up at about $900. And this is where it gets interesting. Analyzing the cost of FirePick 1 revealed big chunks of change going towards certain things like ESD mitigation. FirePick 1 uses Ponoko anti-static plastic 2D laser cut pieces, collectively $200. Neil called me up and said, "Hey Karl, I have carbon nano-tube 3D extrudable plastic--it's ESD safe." When I heard that, I just started laughing. I would have done cartwheels but I'd have killed myself being a klutz. Cheap ESD safe parts. Wow.
That wasn't the only cost mitigation prompted by Neil. FirePick 1 relies on Shapeways for accurate SLS 3D printed parts under the assumption that extrusion printers were cantankerous and inaccurate. Total cost, for Shapeways FirePick 1 parts was about $200. I might have been right about 3D extrusion printing limitations 2 years ago, but the revolution in home 3D printing now fields machines that rival the accuracy and utility of SLS. Once again, Neil demonstrated a way to shave off a chunk of change and speed up the development cycle for mechanical parts from weeks to hours.
Lastly, FirePick 1 relied on the TinyG motor controller and even then it also requires a custom board as well as a Raspberry Pi, so the electronics costs also hovered in the $200 range. Neil said, "heck, we can do better." And several team members have put their heads together to make that custom board happen. Currently we're all using RAMPS/Marlin, but only as scaffolding for future iterations.
In terms of robustness, we hope that the open sharing of the FPD design ensures that we have a scientific basis for comparison since the machines are quite similar (300x300x500mm). We trust that this will enable a natural and rapid process of selection towards robustness and turnkey viability. In practice, I can assert that FirePick Delta is much easier to build and more robust than FirePick 1. We'd like that trend to continue.