That's $4 per TB-month. Meaning you're effectively paying more than the cost of a 1TB hard drive replaced every year, for every TB you're storing. Plus fees to get your data back out. An 8TB drive, replaced every year, is half the cost per TB, with no additional access cost.

Depending on how price conscious you are, I agree with the GP's "keeping it cheap is tricky". And with things like backup, even if you do it yourself, the time spent maintaining it should be negligible: Occasionally kick off a format shift or failed drive replacement, have scripts running everything else.