There were 4M slaves in the USA in 1860. Prices varied wildly, but $750 to $1000 is quite conservative as an average.
That would mean $3,000,000,000 to $4,000,000,000. At a time when the entire federal budget for 1860 was $60,000,000.
IOW, buying the slaves would have required federal taxation to expand by orders of magnitude, causing the very expansion of the federal government that preventing the war would have supposedly allowed.
This ahistorical notion that buying the slavers out would have been infinitely cheaper is shown to be utter nonsense by the reaction of Union slaveowners to offers of compensated gradual emancipation. Lincoln tried repeatedly throughout the war to get Union slaveowners to agree to such a program. They rejected it every time, even towards the end of the war when it would seem even an idiiot would realize slavery was on its way out and the smart thing would be to grab what money was available.
Slavery was utterly tied in to the southern way of life, as is made clear by their violent reaction when they thought it was threatened. Financial considerations were not necessarily the most important in their eyes.
Here's an attempt to quantify the cost of the war versus the cost of buying the slaves and freeing them. I don't agree with all his premises, but I thought it was interesting.
http://www.gongol.com/research/economics/slavebuyout/
Ron Paul talking about buying out slaves was a total dodge. If I were the interviewer I would bring up the numbers you talked about and I would also ask him what would you propose the Federal government to do if the slave owners didn’t want to sell their slaves. Force them to sell?
Ron Paul is a total idiot and I can’t stand how there are so many people bamboozled to think he’s the be all and end all for discussions on constitutional issues....