I don’t think you’ll be able to build anything with €100, but you might be able to buy an old PC or laptop locally and use it as is. I’ve never run nextcloud myself, but from I’ve read it’ll be the most taxing service on your list. Everything seems pretty minimal, though I don’t know anything about Photoprism.

A second hand NUC off eBay

The budget is way too low imo.

You could repurpose an old workstation, bought dirt cheap on eBay if you are lucky, but even then you’ll have to get yourself an HDD, maybe multiple of them if you want to have data redundancy.

For anything new your best bet is a 2 bay ready made NAS, but you’ll have to invest around 300€ for the cheapest one.

Everything you want is definitely possible for the budget.

I used an old I5 laptop with 4GB of RAM for a year or two. If you need a lot of storage, an old HDD will be fine usually. A raspberry pi 4 or 5 will be slower, but would still work, but if Norway prices are anything like belgium, an old I7 laptop sips power and will save money in electric costs

A few tips:

• Run nextcloud all-in-one or spend some time optimizing nextcloud. It will help performance a lot

• Unless you are a serious photographer, use Immich, 100%. Immich is a google photos replacement that has a bunch of good user features like accounts and good security and sharing that photoprism just doesn’t. Photoprism is really geared towards professional photographers.

• transmission + wireguard container for a VPN is the way to go …

• radarr/sonarr/lidarr & prowlarr are good to use with transmission

I used to have old ThinkStation as a home server. Even older ones like S20 I have couple of laying around is still pretty capable system (I’m typing this on one) and as they’ve been CAD workstations and things like that when they were new many have 12+GB of RAM already. I got mine for free troguh a work contact, but they should be available via ebay or (preferably) your local version of it for pretty cheap.

Then you just need new drives and their prices have dropped too. 100€ is a bit of a stretch, but if you can get a whole computer from someone in the industry it should be possible. I have a few systems laying around I could get rid of for a case of beer or something, but shipping alone from here would eat up majority of your budget (if anyone is interested in x3550 m3 throw me a message, located in Finland, I might remember the model wrong but that’s roughly in the ballpark).

Other than thinkstations I’d say you’ll want a xeon CPU with at least 4 hyperthread cores, 16GB RAM and all the drives your budget has left. SSD for a boot drive(s) is nice to have, but spinning rust will get you there eventually.

Many rack mounted servers only accept SAS-drives which are a bit more expensive. Tower mounts generally use SATA so you can just throw in whatever you have laying around. The main concern is amount of RAM available. For older systems it might be a bit difficult to find suitable components, so more you have already in place the better. For VM server I think 16GB or above is fine for learning and it might be possible to shoehorn most of the stuff in even with 8GB. Performance will definetly take a hit with less RAM, but with that budget some compromises are necessary.

So, in short, with that budget it might be possible if you have a friend who has access to discarded workstations or happen to stumble in a good deal with local companies. It’ll require some compromises and/or actively hunting for parts and with old hardware there’s always possibility of failure so plan accordingly.

If you want to start try to find something used on DBA, like an old laptop. If you are an student, maybe someone in your class upgrades their laptop and you can get it cheap. (Best a laptop where you can remove the battery, plus you need to change a setting so it doesn’t go in standby when closing the lit)

You can add an external hard disk for nextcloud data.

My first home server was an raspberry pi, it’s not great for nextcloud, you need to disable all preview image, and the UI might still be slow. Untop using an microSD card for the OS might randomly break (happens to me, SanDisk).

My second server was my old laptop, I used an laptop with i3 from like 2013 as server for a long long time.

Best thing I can recommend is to not rush and get the first best thing, try to look for a good deal. Start small and you can always increase your server in the future.

Wish you the best.

Does budget include storage? Tight budget without storage, even tighter with…

If power usage not a concern then used x86/x64 gear is probably the way to go. Surplus gear (corporate, university…) possibly an option for you. That’s a very tight budget though, so I don’t think it really gives you the luxury of choosing specs unfortunately. That said: I might go fot the best bones/least RAM/storage if you think you might upgrade it down the road. 4GB RAM with an upgrade path to 32 is preferable to 8GB non-upgradable IMHO. Likewise, 500GB spinny disk with extra bays and an NVME slot is nicer than 500GB SSD with no upgrade path. Again… really tight budget so this may all be out of the question.

I’m a fan of low power gear, so I’d recommend something like a Raspberry Pi 5 8GB, or another SBC (I just grabbed an Orange Pi 5 Plus and I like it so far — NVME, 16GB RAM, dual NIC). However these will be out of your budget, especially once you add case, power supply, and storage.

Good luck!