It cost me 450 to make 10 PCBs here (it's 4 layer btw with 0.5mm pitch components), so one board in this quantity is around 60USD locally. Doing for example one or two PCBs would be even more expensive, so that's the figure I based that on. And doing more than a few by hand is really not a good idea, as you can read in How to build.
But I can ofc change that, just tell me what figure would be adequate.
I would just call it very difficult, price varies so much all over the world it is a hard thing to be absolute about.