Seagate has introduced the Exos M series, a range of enterprise-grade mechanical hard drives available in 30TB and 32TB capacities. The two models, the 30TB CMR ST30000NM004K and the 32TB SMR ST32000NM003K, each offer a minimum of 3TB per disk and use a standard 3.
Cheapest is probably a Raspberry Pi with a USB external drive. Look up “Raspberry Pi NAS,” there are a bunch of guides.
Or you can repurpose an old PC, install some NAS distro, and then configure.
There are a ton of options, very few of which require any programming.