I'm looking for a reasonably priced backup drive. Something I can backup critical data to from time to time... but I need something that is reasonably priced.
Well the best cost per gigabyte is going to be an external 3TB USB drive. You can find them on sale for $100.
There's not much difference in reliability between brands at high capacities. They are pretty much all shit.
If you want something more reliable then I would get a 1-2TB 3.5" internal drive with a 5 year warranty and put it into an actively cooled USB3 enclosure.