S19 is roughly 3x the cost of an S9, uses roughly 150% more power, but has around 7.5x the TH.

It would perform even better in this model than the S9.

I just went with an S9 as it is a cheap and approachable miner, is often used for underclocked "pleb-heater" builds, and seemed like the base case for arguing against novelty miners like the Bitaxe.

I cannot argue with the fact that novelty miners represent an easy entrance for newbies, and offer a simpler and less infrastructure-intensive introduction to mining. All I argue is that they are hardly the most economical method for gaining this educational experience, despite often being marketed as such. 

 yeah I didn't read your note fully when I responded - s9 is a better comparison for sure.

"All I argue is that they are hardly the most economical method for gaining this educational experience, despite often being marketed as such." - this, this is my gripe. If you ordered the parts yourself from aliexpress and PCBexpress, you'd be paying 200 in total including shipping for about 5 units. Now you'd still have to fabricate it but still...  

 Thank you for that clarification on pricing. 

I hadn't been aware that one could assemble their own, and had only seen them for sale as fully assembled units with a seemingly uneconomical price tag. 

 nah it's open source and here is the repo: https://github.com/skot/bitaxe

Everything you need is there, step by step.