I was tempted to say $0, but then I thought harder about the problem.
Technically I do have ongoing costs
- PAYG costs for Usenet-news (iirc, $22USD for 500GB block)
https://usenet-news.net/index1.php?url=home
- News indexer (I think...$60 every 5 years?)
Electricity (whatever tiny amount raspberry pi sips). At a guess, maybe $50/yr.
So, amortised over time - very low but not zero. In theory, if I dropped Usenet, it would even lower. And theoretically, I could run the pi off a single solar panel and a diy solar kit but I'm not busy pretending to be Robinson Crusoe just yet. Though... It might be a cool project.
Yarrr! But it really mostly is Yarr these days. So don't go firing up Trumpet winsock to check Forte Agent :)