uhm, i’m a complete newbie in this regard, so i’m not really sure that there was a difference for all of them like that 💜🤔
Discussion
If you buy hardware, either a single board computer or a refurbished laptop/thin client it'll be in the ballpark of $100 - $200 minimum.
Power consumtion is in the order of 10/month, might be a little lower or higher, depending on local rates and above hardware. Power must preferrable be stable.
Assuming you already pay for internet, so can't count that. For lightning and if you want to have a public relay, internet must be stable.
But there's other options: just running bitcoin for yourself, you can probably do that on your daily driver laptop/desktop with no extra cost. If you have an always on machine, you could run lightning there as well, but not recommended.
For nostr, no idea, depends on the usage. If it's a relay for yourself, that can run on virtually anything. A big public relay can get very expensive fairly quickly, mostly for storage and bandwidh requirements, as you probably can't run those from your home connection.
The rest of the cost is time spent, can't value that for you.
My recommendation if you a newbie is start with a bitcoin node.
nostr:npub1rxysxnjkhrmqd3ey73dp9n5y5yvyzcs64acc9g0k2epcpwwyya4spvhnp8 has some great tutorials.⚡️