To the OP who lives in Andersonville, like I do: On Sheridan rd. from Foster to Lawrence there are a series of little ghetto groceries. All of them carry Faygo 2-liters and at a discount. The one across from Big Chicks in particular has a huge display. They have, cold, cans 2 for $1. And I think the 24oz bottles for less than $1. Your quest is over.
Those stores also sporadically carry Better Made chips, which I understand is also a Detroit/Mich thing. I think they have passed Jay's in quality and certainly in price. I love finding regional stuff in oddball places. I imagine it is sort of supplier surplus from those areas. Used to be able to find Cotton Club Less Sweet Ginger Ale, an Ohio favorite, around town once in a while.