Yes, I think it would have been nearly impossible without an enormous emission of debt. In his discussion of the issue apropos Texas's social and economic development in the antebellum period, T. R. Fehrenbach, my manual source, gives the economics of emancipation thusly:
"Aside from the emotional questions of right or wrong, or subordination and equality, emancipation by 1860 had become economically unreasonable. In Texas, the assessed value of all slaves was $106,688,920 -- 20 percent more than the assessed value of all cultivated lands. Whatever its moral capital, the South had invested its economic capital in blacks. Like many another capitalist or dominant group before and since, the Southern gentry, in coping with a labor problem, had fallen into a terrible cultural and racial trap. It was more vulnerable to criticism than either the Northern industrialist paying out slave wages or a government using forced labor, because the cotton planter was creating no fruits for the descendants of his workers to enjoy. [This is a huge, overlooked point about slavery.] The great mass of Negroes were never expected to rise out of bondage. And the profits of the plantation economy were rapidly creating a new leisure class that, however admirable in many respects, was already an anachronism in the 19th-century Western world.
He goes on to compare the planters to the old 18th-century squirearchs of the Atlantic seaboard, who in the North were shoved aside by the Millocracy but who continued to lead society and its affairs in the South.
The arithmetic is such that it would have taken a national undertaking and debt issue to redeem the slaves, and would have taken generations to work off. But even at that, as Fehrenbach points out, the slaves would have come out of bondage in many cases with only the shirts on their backs and nowhere to go. Even the abolitionists didn't have a clue what to do afterward, and Lincoln, in his letters, professed his own shortage of answers in the 1850's.
You are correct. Even in his eulogy to Clay, he recognized both the economic problem and the human problem of the constructed 'racism' of emancipation. But during the war, Lincoln often pointed out the costs of the war per day/month/year vs. the value of the slaves in a given state.
IMHO, the rational answer (by 19th century realities) to slavery was a gradual, compensated, emancipation with a combination of education and resettlement to the territories and/or colonization. The fact was that the very small but politically powerful southern aristocrat class of the south prevented any serious movement in that direction in order to preserve the status quo in their favor and to the determent of 95% of the nation. They manipulated policy and opinion for no other purpose than maintaining their elite status.
The south should not blame the civil war on Lincoln (or the Abolitionists who never had one-tenth the political power of the much smaller elite planter class.) The guilt of 600,000 dead and the trials and troubles that followed, rightly belongs on the memory of the southern aristrocrats! It is revisionism in the extreme to do what DiLorenzo and the rest have done in absolving the southern aristocrats while calling it Lincolns needless war. The war was indeed needless in that the vast majority, North and South, did not want or need slavery. But the war became inevitable because of the pure arrogance, greed and refusal to compromise by that small but powerful faction. They deserve no fond memories ---- IMHO.