I built a server a few years ago in a Fractal Design Node (big square box) which has 4 6TB drives in raid 5 for 18TB of storage and a 6 core AMD cpu. It cost around £1200 and half of that was the hard drives.

It’s been really good, so if you’re looking to build one yourself I’d recommend having a look at the case and the price of drives.

There’s a brexit joke in there somewhere

(quoting from wikipedia) In 2023 a group of engineers modified a dynometer to be able to measure how much horsepower a horse can produce. This horse was measured to 5.7 hp (4.3 kW)