I know. You pretty much need to know what you're doing. And do the maths. Know the reliability (MTBF/MTTF) and price. Don't forget to multiply it by two (as I forgot) because you want backups. And factor in cost of operation. And corresponding hardware you need to run to operate those hdds. My hdd spins down after 5 minutes. I live in Europe and really get to pay for electricity as a consumer. A data center pays way less. My main data, mail, calendar and contacts, OS, databases and everything that needs to be there 24/7 fits on a 1TB solid state disk that doesn't need much energy while idle. So the hdd is mostly spun down.

Nonetheless, I have a 10TB hdd in the basement. I think it was a bit less than 300€ back when I bought it a few years ago. But I can be mistaken. I pay about 0.34€/kWh for (green) electricity. But the server only uses less than 20W on average. That makes it about 4€ per month in electricity for me. And I think my homeserver cost me about 1000€ and I've had it since 2017. So that would be another ~15€ per month if I say I buy hardware for ~1100€ every 6 years. Let's say I pay about 20€/month for the whole thing. I'm not going to factor in the internet connection, because I need that anyways. (And I probably forgot to factor in I upgraded the SSD 2 times and bought additional RAM when it got super cheap. And I don't know the reliability of my hdds...)

I also have a cheap VPS and they'd want 76,27€/month ... 915.24€ per year if I was to buy 10TB of storage from them. (But I think there are cheaper providers out there.) That would have me protected against hard disk failures. It'll probably get cheaper with time, I can scale that effortlessly and the harddisks are spun up 24/7. The harddisks are faster ones and their internet connection is also way faster. And I can't make mistakes like with my own hardware. Maybe having a hdd fail early or buy hardware that needs excessive power. And that'd ruin my calculation.... In my case... I'm going with my ~20€/month. And I hope I did the maths correctly. Best bang for the buck is probably: Dont have the data 24/7 available and just buy an external 10TB hard drive if your concern is just pirating movies. Plug it in via USB into whatever device you're using. And make sure to have backups ;) And if you don't need vast amounts of space, and want to host a proper service for other people: just pay for a VPS somewhere.