Median income in Tanzania is ≈ $1,800pa, so this property is around 5 times the median annual salary.

That said, housing in first world countries is generally a significant multiple of annual median income. In the UK, banks typically lend at 3–4 × an individuals salary or 3 × a couple's combined salary, so a single median earner on around £40k could borrow £120k – £160k.

The article notes the pricing is out-of-reach for many people in Tanzania, but it's also not wildly disconnected from salary:housing ratios in high-income economies.

Also i doubt Tanzania has the code/zoning insanity of the US. You build your hut for cheap and quickly, then you put your concrete house next to it and build it over 10 years as you get money. Probably shared across a larger family. In places like US this impossible; you can only build 1 house on most plots and permits aren't amenable to slow progress so you need a loan and a gigantic pile of money all at once.