The topic is interesting and necessary - the formation of a financial cushion / reserves for the implementation of some plans.
And the model is not bad. Although I would add as one of the mechanisms of achievement - this is the rejection of bad habits and unnecessary purchases.

But what I do not agree with is to evaluate in a specific amount, for example, dollars. Different countries have completely different living conditions. And somewhere 3000 dollars a month is a small salary, in other countries it is an unattainable amount.
Therefore, the correct estimate is the percentage of income, and probably some coefficient, linked to the average acceptable level of income in the country. Then you get a realistically calculated level of monthly deductions to achieve some goal. And comparing $ 300 for the Congo and Switzerland, for example, is a useless topic.