Hii inaitangwa 'back of the envelope mathematics'. Lets dissect the umeffi posted.
Firstly being single does not mean living alone. You could be hosting your relatives or you could be living with a room mate. Of course a 1 bedroom house would be better off that a single room.
Secondly the reasoning that you can save money for other 'useful/better' things is a fallacy. If you can afford a one bedroom house go for it, if you can afford a 2/3/4 bedroom go for it. Life is what you make and if you feel happier and more satisfied living in a 2 bedroom house when single then knock yourself out.
To the maths: A brand new boda boda requires around 80K to buy. Ukiweka insurance and some other expenses it all comes to ~100K. You will then need a rider and also be actively involved in the boda boda affairs. All this will require active participation from the single guy. This means extra responsibility, more risks, stress za boda kuharibika, kanju, polisi and cartels. At the end of the day the boda will bring more stress to you and you are better off living in the 20K 1 bedrrom house.
Anyway if this business was as good as the twitter fellow puts it then all employed people who can afford a monthly saving of 10K would be running tens of bodabodas each as a side hustle.