Communists must adopt the maximum income claim. This demand makes it possible to directly gather the mass of the proletariat and the poor peasantry on the basis of a clear and understandable economic datum, and to reject people who will never be communists or revolutionaries in any way.
No gross income should be greater than 2 times the world GDP per capita, ie ~ $ 36,000 per year in purchasing power parity (price: USA, 2019).
2 times the world GDP per capita PPP is an arbitrary figure: the key is to have an interesting figure to bring together the mass of the proletariat and the poor peasantry. In the revolution, more resolute measures can be implemented to impose more fully equality (a maximum level of consumption, in particular).
The surplus must systematically be collectivized.