LOL who says the slaveholders would have sold. The Deleware slaveholders were offered the same deal. They refused.
Obviously the price and conditions were never right, were they?
LIke any emminent domain action, the owners are not likely to willingly sell at bargain basement prices offered at the end of a rifle barrel.
I think the point is that the war wasn't about freeing slaves, that there were other alternatives if that was the desired result.
Today we'd have a cash for clunkers program to trade in your old labor for some government approved system.