I assume "East" meant the North Eastern coastal areas.
I was able to turn up some information that might help. I did find a table of cotton manufactures by state, grouped by region in the 1860 edition of the book "Southern Wealth and Northern Profit" by Kettell.
He lists as Southern states all the ones on the map of Southern states that I posted a link to earlier in post 1536. On the map the Southern states included Missouri, Kentucky, Maryland, and Delaware. Kettell includes those four states with sll of the other Southern states. The Southern States had cotton manufactures in 1850 of $9,367,331.
Kettell groups the states New Jersey, Pennsylvania, New York and all the New England states into another category. I suspect he would call that group either the North or the East or the Northeast for that matter. Those states had cotton manufactures of $52,062,953 in 1850.
Kettell lumps the rest of the states and territories together in a third group that includes the Western regions Utah, New Mexico and Oregon as well as what we know today as the Midwest (Ohio through Iowa, Minnesota, etc.). Only Indiana and Ohio had any cotton manufactures by 1850. By Kettell's logic, California would fit in his Western group. The Western group totaled $438,900 worth of cotton manufactures in 1850.
Kettell also makes the point, "...If a Massachusetts factory can make a certain style of cotton goods as cheap as the English, it has a duty of 20 per cent., and 10 per cent. charges, or 30 per cent. preference over the English, which insures it the market at a large profit.”
I note that by 1860 there were a number of mills in the South making cloth and other cotton goods. They would have the advantage of much reduced transportation costs to get the cotton to the mills, but perhaps not the possible economy of scale of Northern mills if Northern mills were larger than Southern ones. The South could possibly export any excess cotton goods to Mexico or other places in the Gulf or Caribbean regions and have a transportation cost advantage over English or Northern cotton goods.
Something I wish to point out was the threat analysis which was done by the Financial Elite of the North East. In 1861, they did not know how many states would ultimately join the Confederacy, so they would have regarded the threat that Missouri, Kentucky, Maryland and Delaware joining the Confederacy as a real possibility.
In other words, they made plans in accordance with what they thought could or would likely happen, because they had no way at the time of knowing for sure what was going to happen. That it ultimately did not happen could not have been known to them at the time.
Meaning, they saw the potential economic loss of those other states joining the Confederacy and responded accordingly.
I think war was a necessary step to prevent future secessions. Once the other states saw the increased profits from free trade in an independent South, the pressure would be on to join them. Of course this leaves the North Eastern trade monopolists in a bad position.