How can “estimated somehow” be relevant?
It appears that you are totally unfamiliar with any of the census data for 1860 and do not know how to research.
When and if you want to get around to learning, I will be glad to recommend a few books to you.
Until then, be ignorant my friend. Be ignorant.
I have examined that census which is very comprehensive if you want to know the number of idiots in Pulaski County or the number of blind in Ashley County. But if you are looking for information on per capita income you are SOoL.
In 1860 people would have believed it unconstitutional to even ask about income.