For my single user instance, I can be charitable and say that it’s running on hardware that I already had that is running regardless on spare otherwise unused resources with a already registered domain so the only cost is time spent setting it up. Or I could apply all the costs from the server Lemmy, then it would be about $1200 initially plus ~$10/mo per user.
For reference, Air Canada would need to give ~91% raise to get pilot pay back in line with where Air Canada pilots were in 2001. Post 9/11 the pilots took a terrible ‘save the company from bankruptcy’ deal, then during negotiations in 2012 the government forced a return to work deal with another terrible pilot contract.