I know I put a post previously why phones should cost 30K at the very least. I know I got insulted here. But my advise is that you save up.
I know you will dismiss my counsel.. but it won't be the first time I got insulted but someone who came later on to thank me for my advice.
If you want a cheap phone tafuta a feature phone which will cut your budget by two-thirds. I highly recommend Nokias with a 5K tag. They have a camera, 4G, an app ecosystem and a secure OS. Try Kaios should be great.
Pesa weka kwa moneymarket ya Zimele and save up to 30 - 35K then buy a 2019/20 flagship. Galaxy 10se and even the 10 should be okay.