Well there are many ways leading to Rome. Here is one:
Hybrid home server / cloud provider model.
Public relays and webserver
3X Public relays across globe + 1 web server. All with fixed ips and daily snapshots and sufficient disk space and cpu/ram. Around 135 usd per month.
Setup time and setting up automation, security and monitoring roughly 10 hours (most time to setting up webserver).
Core block producer home computer and core relay home computer and cold laptop
Estimated 5000 usd cost for computers and network equipment (routers, sfp cabling etc. included.)
Cost spread out over 3 years = 139 usd per month.
Hetzner server in germany 50 usd per month (relay / jormungandr / folding at home)
Redundancy / connections
2 Internet connections for home for redundancy. Roughly 110 USD per month. (2x 1gb fiber)
2x UPS (included in computer hardware costs
Learning time and setting up during itn: 6 months roughly 30 hours per week first 3 months (honestly I think it was way more than this I remember spending my christmas and new year checking in on the servers) but its a fair estimate of the work required I guess, then 5 hours per week last 3 months. Total 420 hours work. Example of work: Security, scripts, monitoring, backups, marketing / webpages and pr.
Estimated monitoring and setup time during main net first period FF: 30 hours per week first three months (may june july) then 10 hours per week (augst/sept) 400 hours.
Total work hours over 10 months = 830 / 10 = 83 hours per month on average. (ff and jormungandr overlapped last month). Total costs per month 434 usd. Edit: Forgot to add electricity: Since have very power efficient hardware (on purpose) the cost here is minimal. We are talking like 5-10 usd per month or less.
Work is very much front loaded once you write the scripts and monitoring you need mostly to do upgrades and continued security monitoring and key refreshing routines. Since there are upgrades such as adding oracle services you can put more hours into it as well. But 5-10 hours per week or more if you do more marketing is to be expected imho.
In my case you could argue you do not need public relays in Japan, Usa and Australia and certainly not to keep up a jorumangandr network and have a relay in Germany as well. This would cut my costs in half if I did not. But for the health of the network I am trying to run a strong public relay network. We already see in many epochs that some relays crash so it is nice to have redundancy. It is also nice to have good routines for scale as I have developed over this 11 months now and I would like to keep such a system in place in case we will have to scale up further.
Finally an important price point: Price of being part of history with Cardano, attending conferences and virtual seminars, helping out as a guardian, offering feeback in multiple feedback groups, participating in treasury projects, cips, guild tool discussions, forming organizations etc etc.: Priceless.
Oh and I dont dear to think if I include that into my work hours lol.
Also another cost that is less often mentioned: Having to disclose information about yourself and also your pledge and locking up your ada in pledge are huge costs to pool operators both in the near term but also the risks for the longer term. We are basically walking targets. You do this if you really care about Cardano there are other ways to earn money more safely. (day job comes to mind as one way…)
Finally a key point and why we see so many multiple pools: Cost of adding a 2nd pool using my hardware structure = 0 usd per month. Cost for me to add around 20 pools = 0 usd. Monitoring time would be roughly the same as I already implemented the monitoring and scripting solutions so still 5-10 hours per week (including pr/marketing).