The low-cost services don't seem able to directly eat Eagle-format files, so I could only price it on Eurocircuits [1] where it came out to €50+ which seems like a lot.
Strange for an open project to publish in a proprietary format.
It looks like the files are in an older, binary Eagle file format. Importing it into a newer version of Eagle and saving it in an XML format would be the first step. After that, KiCad might be able to open the files if you prefer an open-source tool. From that you could export Gerber files for the fabrication houses.
A board of that size with just two layers should be $2 + shipping for five boards with e.g. JLCPCB. A bit more if you want to go lead-free.
The low-cost services don't seem able to directly eat Eagle-format files, so I could only price it on Eurocircuits [1] where it came out to €50+ which seems like a lot.
Strange for an open project to publish in a proprietary format.
[1]: https://be.eurocircuits.com