It was an analogy. India has a population about four times that of the US, so India is roughly akin to the North, and the US is roughly akin to the south, in terms of the ratios of their populations.
Clearly India does not purchase more of these various goods than the United States, so having a population four times larger does not automatically put money into their pockets to pay for imported goods.
The United States has money and so they buy imported goods.
In 1860, the South produced 73% of the exports, and it was those exports that actually paid for European goods. The North only produced 27% of the exports, so they could buy 27% of the European goods being imported.
Yes, this is a very simple way of looking at it, but it is roughly accurate.
You are trying to have me believe that the 20 million Northerners who only earned 27% of the income, were paying for the vast majority of the import goods.
You tell me they were getting the money through diffuse means, but which always end up somehow getting it out of Southern hands.
Yes, the North and South bought each others goods, and it was all a complex system, but ultimately the value created to purchase the European products had to come from the South at the rate of 73% of the total. (85% if you believe other sources.)
Other way around. The North had something like three times the income of the South.