Well, the mystery has been solved...sort of. I put the issue to my International class this semester and John Pulito found a paper discussing that exact quote-- in the QJE, by F.W. Taussig in 1914.
The quote at question is the following:
"I do not know much about the tariff, but I know this much, when we buy manufactured goods abroad, we get the goods and the foreigner gets the money. When we buy manufactured goods at home, we get both the goods and the money."
Interestingly, the article is actually about how Lincoln likely never actually said it. Parsing through his notes from 1847-1867 there are some intimations that he believed the general premise of the above quote, and mentioned something similar at a speech in Pittsburgh in 1861, but in no recorded place can anyone attribute the exact quote to Lincoln. As best as I can tell, no one has taken up the issue again.
So my conclusion is this: If presented with this quote, Lincoln would have agreed, but he seems to have never spoken those exact words.