In 2018, I spent about six weeks running a series of tests to measure Sia's real world costs. At that time, storage cost ~$4.50/TB on Sia to back up large real world files (backups of DVDs and Blu-Rays).[0] Community members have re-run my tests every few months, most recently in October 2019, when the cost was measured at $1.31/TB, though it's worth noting that recent tests use synthetic data optimized to minimize Sia's cost.[1] It's also unclear how much the market value of Sia's utility token affects these costs, as the price of Siacoin has fallen by ~80% since I conducted my original set of tests.

The calculations in today's blog post account for the labor cost of assembling hardware, but leave out major other labor costs:

1. You need an SRE to keep the servers online. Sia pushes out updates every few months, and the network penalizes you if you don't upgrade to the latest version. In addition, to optimize costs, you need to adjust your node's pricing in response to changes in the market.

2. You need a compliance officer to handle takedown requests. Since Sia allows anyone to upload data to your server without proving their identity, there's nothing stopping anyone from uploading illegal data to the network. If Sia reached the point where people are building $4k hosting rigs, then it's safe to assume clients would also be using Sia to store illegal data. When law enforcement identifies illegal data, they would send takedown notices to all hosts who are storing copies of it, and those hosts would need someone available to process those takedowns quickly.

[0] https://blog.spaceduck.io/load-test-wrapup/

[1] https://siastats.info/benchmarking