Selfhosted

The sub-$300 is increasingly dying because of the RAM prices, but anything with a N100 or N150 should be enough for your usage case.

Stop ordering from Amazon

It won’t be on Amazon, but I found a ton of older generation Mac minis available on Craigslist in my area. I picked one up for $50 and installed Ubuntu server. Thing’s been running like a champ for 2 years.

Edit: should have fully read your post. No idea about installing truenas on it. I’d assume most would be single ssd machines.

Just about any of the Intel N series minipcs are often suggested for just Jellyfin. I haven't looked at them too much yet.

Ask your local university facilities department about their overstock policy. The university of Arizona literally has a warehouse where you can peruse their old computers and furniture and buy at Craigslist prices.

University surplus. I work for a university and we get rid of stuff all tfe time that is still very useful.

Ask a local ISP like us. We store our old servers and send them to be recycled annually. If I had an enthusiast walk up to our offices asking for a donation, we wouldn't hesitate. Can't speak for competitors, but it's worth a shot.

Thinkcentre Tiny, Dell Optiplex Micro, or HP ProDesk Mini. Prices have gone up the last few months but they’re still a solid value. Most sellers ship pretty quick these days.

Wondering what is a good sub $300 computer I can order that will run Jellyfin, Immich, and a few light services off of?

A lot more options than you think. The Tiny/Mini/Micro PCs are fantastic for what they are, even one running a 7th gen Intel CPU is more than plenty.

A mini PC could certainly work! If you're willing to go ebay, I'd recommend any of these Lenovo Thinkcentre SFF PCs:

https://forums.servethehome.com/index.php?threads/lenovo-thinkcentre-thinkstation-tiny-project-tinyminimicro-reference-thread.34925/

1-2x m.2 slots, 1x 2.5" slot, and some can accommodate a half-height PCI-E card in place of the 2.5" slot. Presumably, you'd want to go Intel for QSV

Any used PC or laptop that can run Linux.

I use Intel NUCs off eBay for this kind of stuff. A few years ago you could get one for ~$200 on eBay.

Dell optiplex

There are companies selling off PCs that are "too small" for Win11, really cheap. More than sufficient for a NAS. You might even get a bunch of them, chose the best mainboard/case/PSU set, put the others in storage, and get all the RAM and HDD in one box.

A big fan of the HP elite desk line. Specifically the mini form factor. Also the Intel version for quick sync.

iGPU for low power draw, but can still handle a transcode or two for Jellyfin.

Cheap as a refurbish on eBay.

My server is currently sitting at 1.5 years of uptime, hosting Jellyfin, minecraft, adguard, and a while suitr of other tools!

I always used my retired PCs and parts but then my kids all wanted gaming rigs so spare PCs and parts do not exist in my world anymore and they tended to be too big, noisy and inefficient.

I would go for used ex-corporate desktop mini PCs from the likes of Dell, HP, Lenovo. Perhaps don't go for the smallest ones if you want to be able to get into them and add stuff. They tend to have reasonably good idle power and noise and its common to find ones supporting two nvme ssds. Intel cpu with quicksync for jellyfin video decode if you aren't adding discrete gpu - check supported codecs. Codec support varies across generations I think.

I would stay well away from laptops: bad thermals, power limits, limited expandability and SBCs like RPi which have poor io for servers.

I picked up an old HP Elitedesk off ebay a few years ago. I added a few TB of SSD and another stick of DDR4 when that stuff was cheap. It supports two nvme ssds as well as space for sata drives. Apart from media storage I can't see any compelling reason to want to upgrade it.

Find something on craigslist or local pickup on ebay, check government/police surplus, or do some freecycling. At least in my area a lot of people leave their e-waste computers at Best Buy, often in the doorway, nobody cares if you come and pick them up. Even if they're broken (and they're often perfectly functional and sometimes surprisingly powerful) it likely only takes a few before you've got some functional combination of parts.

It's likely not as much of a picker's heaven anymore since I imagine the huge wave of windows-10-obsolete computers being thrown away for no reason has probably mostly subsided, but there is so much old and perfectly functional stuff out there it's really unjustifiable to be buying something new especially at today's modern prices.

My last build and current have been a Thinkstation and a z series workstation, both used from ex-gov auctions, were decently priced, will run everything you wanna throw at them.

They do come at the cost of increased power draw, but since I've put in solar I'm not worried about that.

If you want a NAS on the cheap my preference is just get any cheap "normal" PC, a case with a good amount of HDD bays. Move the drives into the PC, and you have all the expand ability you could dream of. You can find plenty of DDR4 machines for cheap now. Then as ram prices come down you can go up to 128gb of ram as long as your board has 4 slots.

Anything on craigslist/FB marketplace will work.

Where you happy with the Lenovo thinkcentre? You can often find replacement motherboards for these. It will be cheaper than any of the alternatives here.

A refurbished Dell optiplex has been my move. Hasn't failed me yet.

Set aside some for surge protection/UPS

You can go far below $300 with very little practical performance compromise, but I wouldn't even look on Amazon with memory prices being what they are lately. Get an old DDR3 era Optiplex desktop on eBay, throw a $25 Quadro P400 in it for transcoding, and transfer your existing SSDs over. Tons of eBay listings have 2-4 day shipping. With DDR3 you can easily get 16GB of RAM for like $30 if it doesn't have enough already. Avoiding DDR4/DDR5 will save a ton of money so it's essential to buy used.

The SSDs and hard drives for the array are by far the most expensive part. I've been using an underclocked and undervolted Ryzen 1700 in my server for 6 years now and have zero complaints around CPU performance. I did eventually need more than 16GB of RAM last year, but the only outright failures I've had are on the various component's fans.

The key here is old hardware. I built a TrueNAS box out of an old Dell Optiplex 990. I got it from a friend for free but you can find one online for well under $200. Later you can upgrade the box bit-by-bit if you care to. I upgraded the case, motherboard, cooler, and power supply over time. It’s been a capable NAS for several years even though it’s using a 2nd gen Intel core i3.

So a trick for the double drives is to pop in a low profile usb drive and install the os on that. Then you can use the ssd/hdd for other things.