More than zero. MAGIX acquired freedb in 2006, so I assume this decision was an easy one for some middle manager who has been there for a couple years and has no love for some crusty Old Internet service that's beyond obsolete (aka can't figure out how to put ads on it).
This corporate "has to be profitable" mentality needs to die. It's sad that we are in a place where even simple services require these supposedly ongoing maintenance costs, when they were originally designed as set-it-and-forget-it services
How can a "set-it-and-forget-it" web service exist from the service provider's POV? You always need to do small things like monitoring your servers and making sure they're all up-to-date and still working. This is ongoing maintenance cost. Additionally, you need electricity and some place to put your servers (be it virtual or physical).
Also, running something unprofitable out of your own pocket works as a hobby maybe, but not for a company at scale. You need to pay your employees. Even as a hobby it's problematic because you can only do it so many times until your regular income is exhausted.
Download: http://www.freedb.org/en/download__server_software.4.html
Every time this happens I get more and more angry about the trash-heap-dumpster-fire services from exit-focused "enterpreneurs" that seek to replace them
How much could freedb have been costing MAGIX? Could they not have handed it off to someone else?