Seagate has come up with 8tb drives. They're sold as "archive", the idea being that they're more suitable for being read from, than for writing to. But they're really really cheap, under £190 (inc VAT). I've just bought half a dozen, because I need to refurbish my colocation servers.
At my colocation, I have customer-facing servers, and servers that are spare, so that if a customer-facing server develops a fault, I can do a switch without having to make an emergency visit. And I now have six failed servers, sitting there doing nothing.
I make a rule of always buying the biggest drives available, because they tend to be better value for money; these 8tb drives are amazing. I remember when I was buying 80 gb drives (1% of the size) for the same price.
I've also bought a load of 1gb memory sticks, because what I do, is build up servers (I'm planning six), load the latest version of Linux (currently 22), test them for a week or two, then take them up to the colocation, swap them for the failed servers, and work on the failed servers back in my workshop.