The Blackview A series is aimed at those who only want to spend very little money on a smartphone. The Blackview A80 comes with Android 10 Go, very little memory, but at least four camera lenses to the buyer. A good offer?
https://www.notebookcheck.net/Blackview-A80-Smartphone-Review-Cell-phone-for-little-money.527308.0.html
If you only have 100 euros, and the Redmi 9 costs too much in your country, I'd go with a refurbished/used smartphone instead. It's frankly bizarre to still see A53 quad-cores in 2021.
I hope that in the near future RISC-V allows for dirt cheap but still functional entry-level android go phones, so everyone can afford one.