Not only are you footing the bill with your tax money, but the government has to borrow the money to give to GM (due to the deficit) which decreases the available capital to invest in economically viable opportunities.
Of course, what the government doesn't borrow, they print, which decreases the value of every dollar in circulation (which also discourages investment).
It's kind of a moot point as the time line doesn't really work... Lincoln never had the opportunity to purchase slaves prior to secession. Nobody knows what would have happened if he had campaigned on such a platform.
The slave states seceded because without enforcement the fugitive slave act, they really had no reason to stay in the Union. The secession was largely pre-emptive, as there really weren't yet any "rights" being overridden with regards to slavery at that point, and Lincoln had no desire to free the slaves in the South until it became politically expedient to do so.
Prior to the Civil War, the general consensus was that states maintained the right to secede as the primary check on the power of the Federal government. Once the South declared their intention to secede, however, Lincoln refused to negotiate the sale of federal property with the Confederacy, then did some fancy political maneuvering to get the public on the side of war (sound familiar?).
Given that every other country in the world managed to end slavery without war, one would think it could have been possible, no?
...the war could probably have been avoided by dealing with slavery in a good way...
Lincoln could have purchased the freedom of every slave in the country for a fraction of the monetary cost of the Civil War-- with the added benefit of preventing 600,000 war-related deaths.
It's not just the South's loss of slave labor, Lincoln also enacted a number of high tariffs and subsidies that strongly favored the northern industry and railroads at the expense of the South.
Lincoln was very much in favor of the mercantilism (aka corporate subsidies) proposed by Hamilton and Henry Clay (who called it the "American System"), and opposed by Jeffersonian democrats.
The first rule of intelligent tinkering is to save all the parts. -- Paul Erlich