All for the affordable price of nine thousand dollars, which is likely more than what a local person makes working for an entire year. It seems to me that the concept of "housing" needs a serious re-think.
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.