68kMLA

It's not really economical to make less than five. You will spend a lot more getting your own PCB etching setup going, and the chemicals involved are nasty. Educational to give it a go, though.

Yeah, given where the costs sit in the process, 5 boards won't practically cost less than one or two. It isn't just the materials you're paying for, it is the engineering, tooling, admin, fixed infrastructure, shop and shipping... None of which scale per board.

Gotta agree with Cheesey on this, it may be more effort than it's worth. CNC or laser engraving PCBs is a chemical-free method, but those too come with steep learning curves and costs. Also consider that anything more than 2 layers is going to be seriously complex to do at home, if possible at all. Unless you're seriously interested in this as a hobby, I'd just order the minimum of PCBs at the cheapo PCB houses.

I've made my own boards by etch and CNC engraving. Isn't worth it. End product is inferior and it is more effort than you visualise. For example, I used to have to 3D map the surface of the bare PCB with a probe before cutting on the CNC and even a fairly small PCB would take 30 minutes just to cut. Prep took way longer.

Same experience as Phipli except with the old chemical bath and whatnot. Doing mine was slower, more expensive and the ones done by PCB prototyping service were better quality and cheaper. Meanwhile you can work on other things

I usually give the extra ones or use them as protection with standoffs

That's also a good point - if you think about where you put some mounting holes on your PCBs you can use two spare ones as the top and bottom of a custom case type thing

5 is good. 2 is too little. what if you mess up the first one and drop the second, you're gonna need a third! and what if the third explodes. fourth time, etc.

You should think of making PCBs as a hobby in itself - if it's something you're interested in, go for it, but like anything else, the people at the factories really know what they're doing. If you've never worked with boards without solder mask and through-plated holes, believe me when I say it's a hassle.

As far as how many boards you get, OSH Park (oshpark.com) will only send you three. I understand you though, fiber glass is extremely nasty from an environmental perspective and I don't like buying more than I need either.