The bar chart might be more useful if they weighted the source with its number of users. Facebook isn’t 7 times more hateful than Telegram. It has around 3.5 times as many users - but also the two are used very differently. I use Telegram, but only as a free messaging platform for automated alerts.
Then there’s the algorithms, which tend to feed you what you engage with and from those connections you’ve made on it. The exception recently is X which has a very strong political bias and has turned into something that pushes hate very strongly.
It’s fine, but not going to be the cheapest.
Cheap to buy: Any old PC desktop, really. Most will run linux and windows fine, depending on what you want. Anywhere from free to £100. If you have an old desktop or laptop already, use that to start with.
Cheap to run: Any mini PC. I run a Lenovo ThinkCentre M53 for low power duties. Cost £40 and runs silently at 10watts, idle. (I have a secondary, much beefier server for other stuff that runs at around 100w which lives in the garage)
But plenty of people do run mac minis as home servers, often on Linux. They’re fine - just do your homework on the CPU ability, how much ram you can add, and whether you’re okay with external disks if you can’t fit enough inside.